---
_id: '11521'
abstract:
- lang: eng
text: 'The cosmic ionizing emissivity from star-forming galaxies has long been anchored
to UV luminosity functions. Here, we introduce an emissivity framework based on
Lyα emitters (LAEs), which naturally hones in on the subset of galaxies responsible
for the ionizing background due to the intimate connection between production
and escape of Lyα and LyC photons. Using constraints on the escape fractions of
bright LAEs (LLyα > 0.2L*) at z ≈ 2 obtained from resolved Lyα profiles, and arguing
for their redshift-invariance, we show that: (i) quasars and LAEs together reproduce
the relatively flat emissivity at z ≈ 2–6, which is non-trivial given the strong
evolution in both the star formation density and quasar number density at these
epochs and (ii) LAEs produce late and rapid reionization between z ≈ 6−9 under
plausible assumptions. Within this framework, the >10 × rise in the UV population-averaged
fesc between z ≈ 3–7 naturally arises due to the same phenomena that drive the
growing LAE fraction with redshift. Generally, a LAE dominated emissivity yields
a peak in the distribution of the ionizing budget with UV luminosity as reported
in latest simulations. Using our adopted parameters (fesc=50 per cent, ξion
= 1025.9 Hz erg−1 for half the bright LAEs), a highly ionizing minority of galaxies
with MUV < −17 accounts for the entire ionizing budget from star-forming galaxies.
Rapid flashes of LyC from such rare galaxies produce a ‘disco’ ionizing background.
We conclude proposing tests to further develop our suggested Lyα-anchored formalism.'
acknowledgement: We thank an anonymous referee for an encouraging and constructive
report that helped improving the quality of this work. We acknowledge illuminating
conversations with Xiaohan Wu, Chris Cain, Anna-Christina Eilers, Simon Lilly and
Ruari Mackenzie. RPN gratefully acknowledges an Ashford Fellowship granted by Harvard
University. MG was supported by NASA through the NASA Hubble Fellowship grant HST-HF2-51409.
PO acknowledges support from the Swiss National Science Foundation through the SNSF
Professorship grant 190079. GP acknowledges support from the Netherlands Research
School for Astronomy (NOVA). MH is fellow of the Knut and Alice Wallenberg Foundation.
DE is supported by the US National Science Foundation (NSF) through Astronomy &
Astrophysics grant AST-1909198. The Cosmic Dawn Center (DAWN) is funded by the Danish
National Research Foundation under grant No. 140. RA acknowledges support from Fondecyt
Regular Grant 1202007. ST is supported by the 2021 Research Fund 1.210134.01 of
UNIST (Ulsan National Institute of Science & Technology). MLl acknowledges support
from the ANID/Scholarship Program/Doctorado Nacional/2019-21191036. JC acknowledges
support from the Spanish Ministry of Science and Innovation, project PID2019-107408GB-C43
(ESTALLIDOS) and from Gobierno de Canarias through EU FEDER funding, project PID2020010050.
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Jorryt J
full_name: Matthee, Jorryt J
id: 7439a258-f3c0-11ec-9501-9df22fe06720
last_name: Matthee
orcid: 0000-0003-2871-127X
- first_name: Rohan P.
full_name: Naidu, Rohan P.
last_name: Naidu
- first_name: Gabriele
full_name: Pezzulli, Gabriele
last_name: Pezzulli
- first_name: Max
full_name: Gronke, Max
last_name: Gronke
- first_name: David
full_name: Sobral, David
last_name: Sobral
- first_name: Pascal A.
full_name: Oesch, Pascal A.
last_name: Oesch
- first_name: Matthew
full_name: Hayes, Matthew
last_name: Hayes
- first_name: Dawn
full_name: Erb, Dawn
last_name: Erb
- first_name: Daniel
full_name: Schaerer, Daniel
last_name: Schaerer
- first_name: Ricardo
full_name: Amorín, Ricardo
last_name: Amorín
- first_name: Sandro
full_name: Tacchella, Sandro
last_name: Tacchella
- first_name: Ana Paulino-Afonso
full_name: Ana Paulino-Afonso, Ana Paulino-Afonso
last_name: Ana Paulino-Afonso
- first_name: Mario
full_name: Llerena, Mario
last_name: Llerena
- first_name: João
full_name: Calhau, João
last_name: Calhau
- first_name: Huub
full_name: Röttgering, Huub
last_name: Röttgering
citation:
ama: 'Matthee JJ, Naidu RP, Pezzulli G, et al. (Re)Solving reionization with Lyα:
How bright Lyα emitters account for the z ≈ 2 − 8 cosmic ionizing background.
Monthly Notices of the Royal Astronomical Society. 2022;512(4):5960-5977.
doi:10.1093/mnras/stac801'
apa: 'Matthee, J. J., Naidu, R. P., Pezzulli, G., Gronke, M., Sobral, D., Oesch,
P. A., … Röttgering, H. (2022). (Re)Solving reionization with Lyα: How bright
Lyα emitters account for the z ≈ 2 − 8 cosmic ionizing background. Monthly
Notices of the Royal Astronomical Society. Oxford University Press. https://doi.org/10.1093/mnras/stac801'
chicago: 'Matthee, Jorryt J, Rohan P. Naidu, Gabriele Pezzulli, Max Gronke, David
Sobral, Pascal A. Oesch, Matthew Hayes, et al. “(Re)Solving Reionization with
Lyα: How Bright Lyα Emitters Account for the z ≈ 2 − 8 Cosmic Ionizing Background.”
Monthly Notices of the Royal Astronomical Society. Oxford University Press,
2022. https://doi.org/10.1093/mnras/stac801.'
ieee: 'J. J. Matthee et al., “(Re)Solving reionization with Lyα: How bright
Lyα emitters account for the z ≈ 2 − 8 cosmic ionizing background,” Monthly
Notices of the Royal Astronomical Society, vol. 512, no. 4. Oxford University
Press, pp. 5960–5977, 2022.'
ista: 'Matthee JJ, Naidu RP, Pezzulli G, Gronke M, Sobral D, Oesch PA, Hayes M,
Erb D, Schaerer D, Amorín R, Tacchella S, Ana Paulino-Afonso AP-A, Llerena M,
Calhau J, Röttgering H. 2022. (Re)Solving reionization with Lyα: How bright Lyα
emitters account for the z ≈ 2 − 8 cosmic ionizing background. Monthly Notices
of the Royal Astronomical Society. 512(4), 5960–5977.'
mla: 'Matthee, Jorryt J., et al. “(Re)Solving Reionization with Lyα: How Bright
Lyα Emitters Account for the z ≈ 2 − 8 Cosmic Ionizing Background.” Monthly
Notices of the Royal Astronomical Society, vol. 512, no. 4, Oxford University
Press, 2022, pp. 5960–77, doi:10.1093/mnras/stac801.'
short: J.J. Matthee, R.P. Naidu, G. Pezzulli, M. Gronke, D. Sobral, P.A. Oesch,
M. Hayes, D. Erb, D. Schaerer, R. Amorín, S. Tacchella, A.P.-A. Ana Paulino-Afonso,
M. Llerena, J. Calhau, H. Röttgering, Monthly Notices of the Royal Astronomical
Society 512 (2022) 5960–5977.
date_created: 2022-07-07T09:21:30Z
date_published: 2022-06-01T00:00:00Z
date_updated: 2022-08-18T10:42:47Z
day: '01'
doi: 10.1093/mnras/stac801
extern: '1'
external_id:
arxiv:
- '2110.11967'
intvolume: ' 512'
issue: '4'
keyword:
- 'galaxies: high-redshift'
- intergalactic medium
- 'cosmology: observations'
- dark ages
- reionization
- first stars
- 'ultraviolet: galaxies'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/2110.11967
month: '06'
oa: 1
oa_version: Preprint
page: 5960-5977
publication: Monthly Notices of the Royal Astronomical Society
publication_identifier:
eissn:
- 1365-2966
issn:
- 0035-8711
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: '(Re)Solving reionization with Lyα: How bright Lyα emitters account for the
z ≈ 2 − 8 cosmic ionizing background'
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 512
year: '2022'
...
---
_id: '11621'
abstract:
- lang: eng
text: "Context. Asteroseismology has revealed small core-to-surface rotation contrasts
in stars in the whole Hertzsprung–Russell diagram. This is the signature of strong
transport of angular momentum (AM) in stellar interiors. One of the plausible
candidates to efficiently carry AM is magnetic fields with various topologies
that could be present in stellar radiative zones. Among them, strong axisymmetric
azimuthal (toroidal) magnetic fields have received a lot of interest. Indeed,
if they are subject to the so-called Tayler instability, the accompanying triggered
Maxwell stresses can transport AM efficiently. In addition, the electromotive
force induced by the fluctuations of magnetic and velocity fields could potentially
sustain a dynamo action that leads to the regeneration of the initial strong axisymmetric
azimuthal magnetic field.\r\n\r\nAims. The key question we aim to answer is whether
we can detect signatures of these deep strong azimuthal magnetic fields. The only
way to answer this question is asteroseismology, and the best laboratories of
study are intermediate-mass and massive stars with external radiative envelopes.
Most of these are rapid rotators during their main sequence. Therefore, we have
to study stellar pulsations propagating in stably stratified, rotating, and potentially
strongly magnetised radiative zones, namely magneto-gravito-inertial (MGI) waves.\r\n\r\nMethods.
We generalise the traditional approximation of rotation (TAR) by simultaneously
taking general axisymmetric differential rotation and azimuthal magnetic fields
into account. Both the Coriolis acceleration and the Lorentz force are therefore
treated in a non-perturbative way. Using this new formalism, we derive the asymptotic
properties of MGI waves and their period spacings.\r\n\r\nResults. We find that
toroidal magnetic fields induce a shift in the period spacings of gravity (g)
and Rossby (r) modes. An equatorial azimuthal magnetic field with an amplitude
of the order of 105 G leads to signatures that are detectable in period spacings
for high-radial-order g and r modes in γ Doradus (γ Dor) and slowly pulsating
B (SPB) stars. More complex hemispheric configurations are more difficult to observe,
particularly when they are localised out of the propagation region of MGI modes,
which can be localised in an equatorial belt.\r\n\r\nConclusions. The magnetic
TAR, which takes into account toroidal magnetic fields in a non-perturbative way,
is derived. This new formalism allows us to assess the effects of the magnetic
field in γ Dor and SPB stars on g and r modes. We find that these effects should
be detectable for equatorial fields thanks to modern space photometry using observations
from Kepler, TESS CVZ, and PLATO."
acknowledgement: 'We thank the referee for her/his positive and constructive report,
which has allowed us to improve the quality of our article. H.D. and S.M. acknowledge
support from the CNES PLATO grant at CEA/DAp. T.V.R. gratefully acknowledges support
from the Research Foundation Flanders (FWO) under grant agreement No. 12ZB620N and
V414021N. This research was supported in part by the National Science Foundation
under Grant No. NSF PHY-1748958. C.A. is supported by the KU Leuven Research Council
(grant C16/18/005: PARADISE) as well as from the BELgian federal Science Policy
Office (BELSPO) through a PLATO PRODEX grant.'
article_number: A133
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: H.
full_name: Dhouib, H.
last_name: Dhouib
- first_name: S.
full_name: Mathis, S.
last_name: Mathis
- first_name: Lisa Annabelle
full_name: Bugnet, Lisa Annabelle
id: d9edb345-f866-11ec-9b37-d119b5234501
last_name: Bugnet
orcid: 0000-0003-0142-4000
- first_name: T.
full_name: Van Reeth, T.
last_name: Van Reeth
- first_name: C.
full_name: Aerts, C.
last_name: Aerts
citation:
ama: 'Dhouib H, Mathis S, Bugnet LA, Van Reeth T, Aerts C. Detecting deep axisymmetric
toroidal magnetic fields in stars: The traditional approximation of rotation for
differentially rotating deep spherical shells with a general azimuthal magnetic
field. Astronomy & Astrophysics. 2022;661. doi:10.1051/0004-6361/202142956'
apa: 'Dhouib, H., Mathis, S., Bugnet, L. A., Van Reeth, T., & Aerts, C. (2022).
Detecting deep axisymmetric toroidal magnetic fields in stars: The traditional
approximation of rotation for differentially rotating deep spherical shells with
a general azimuthal magnetic field. Astronomy & Astrophysics. EDP Sciences.
https://doi.org/10.1051/0004-6361/202142956'
chicago: 'Dhouib, H., S. Mathis, Lisa Annabelle Bugnet, T. Van Reeth, and C. Aerts.
“Detecting Deep Axisymmetric Toroidal Magnetic Fields in Stars: The Traditional
Approximation of Rotation for Differentially Rotating Deep Spherical Shells with
a General Azimuthal Magnetic Field.” Astronomy & Astrophysics. EDP
Sciences, 2022. https://doi.org/10.1051/0004-6361/202142956.'
ieee: 'H. Dhouib, S. Mathis, L. A. Bugnet, T. Van Reeth, and C. Aerts, “Detecting
deep axisymmetric toroidal magnetic fields in stars: The traditional approximation
of rotation for differentially rotating deep spherical shells with a general azimuthal
magnetic field,” Astronomy & Astrophysics, vol. 661. EDP Sciences,
2022.'
ista: 'Dhouib H, Mathis S, Bugnet LA, Van Reeth T, Aerts C. 2022. Detecting deep
axisymmetric toroidal magnetic fields in stars: The traditional approximation
of rotation for differentially rotating deep spherical shells with a general azimuthal
magnetic field. Astronomy & Astrophysics. 661, A133.'
mla: 'Dhouib, H., et al. “Detecting Deep Axisymmetric Toroidal Magnetic Fields in
Stars: The Traditional Approximation of Rotation for Differentially Rotating Deep
Spherical Shells with a General Azimuthal Magnetic Field.” Astronomy &
Astrophysics, vol. 661, A133, EDP Sciences, 2022, doi:10.1051/0004-6361/202142956.'
short: H. Dhouib, S. Mathis, L.A. Bugnet, T. Van Reeth, C. Aerts, Astronomy &
Astrophysics 661 (2022).
date_created: 2022-07-19T08:04:15Z
date_published: 2022-05-19T00:00:00Z
date_updated: 2022-08-22T07:58:54Z
day: '19'
doi: 10.1051/0004-6361/202142956
extern: '1'
external_id:
arxiv:
- '2202.10026'
intvolume: ' 661'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- magnetohydrodynamics (MHD) / waves / stars
- 'rotation / stars: magnetic field / stars'
- oscillations / methods
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/2202.10026
month: '05'
oa: 1
oa_version: Preprint
publication: Astronomy & Astrophysics
publication_identifier:
eissn:
- 1432-0746
issn:
- 0004-6361
publication_status: published
publisher: EDP Sciences
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Detecting deep axisymmetric toroidal magnetic fields in stars: The traditional
approximation of rotation for differentially rotating deep spherical shells with
a general azimuthal magnetic field'
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 661
year: '2022'
...
---
_id: '11522'
abstract:
- lang: eng
text: The decline in abundance of Lyman-α (Lyα) emitting galaxies at z ≳ 6 is a
powerful and commonly used probe to constrain the progress of cosmic reionization.
We use the CODAII simulation, which is a radiation hydrodynamic simulation featuring
a box of ∼94 comoving Mpc side length, to compute the Lyα transmission properties
of the intergalactic medium (IGM) at z ∼ 5.8 to 7. Our results mainly confirm
previous studies, i.e. we find a declining Lyα transmission with redshift and
a large sightline-to-sightline variation. However, motivated by the recent discovery
of blue Lyα peaks at high redshift, we also analyse the IGM transmission on the
blue side, which shows a rapid decline at z ≳ 6 of the blue transmission. This
low transmission can be attributed not only to the presence of neutral regions
but also to the residual neutral hydrogen within ionized regions, for which a
density even as low as nHI∼10−9cm−3 (sometimes combined with kinematic effects)
leads to a significantly reduced visibility. Still, we find that ∼1 per cent of
sightlines towards M1600AB ∼ −21 galaxies at z ∼ 7 are transparent enough to allow
a transmission of a blue Lyα peak. We discuss our results in the context of the
interpretation of observations.
acknowledgement: The authors thank the referee for constructive feedback that improved
the outcome of this study. We are grateful to Antoinette Songaila Cowie for sharing
the ‘NEPLA4’ spectrum with us. This research has made use of NASA’s Astrophysics
Data System, and many open source projects such as trident (Hummels et al. 2017),
IPython (Pérez & Granger 2007), SciPy (Virtanen et al. 2019), NumPy (Walt et al.
2011), matplotlib (Hunter 2007), pandas (McKinney 2010), and the yt-project (Turk
et al. 2011). MG was supported by NASA through the NASA Hubble Fellowship grant
HST-HF2-51409 awarded by the Space Telescope Science Institute, which is operated
by the Association of Universities for Research in Astronomy, Inc., for NASA, under
contract NAS5-26555. MG acknowledges support from NASA grants HST-GO-15643.017,
and HST-AR15797.001 as well as XSEDE grant TG-AST180036. CAM acknowledges support
by NASA Headquarters through the NASA Hubble Fellowship grant HST-HF2-51413.001-A.
PRS was supported in part by U.S. NSF grant AST-1009799, NASA grant NNX11AE09G,
and supercomputer resources from NSF XSEDE grant TG AST090005 and the Texas Advanced
Computing Center (TACC) at The University of Texas at Austin. JM acknowledges a
Zwicky Prize Fellowship from ETH Zurich. GY acknowledges financial support by MICIU/FEDER
under project grant PGC2018-094975-C21. SEIB acknowledges funding from the European
Research Council (ERC) under the European Union’s Horizon 2020 research and innovation
programme (grant agreement No. 669253). ITI was supported by the Science and Technology
Facilities Council [grants ST/I000976/1, ST/F002858/1, ST/P000525/1, and ST/T000473/1];
and The Southeast Physics Network (SEPNet). KA was supported by NRF2016R1D1A1B04935414
and NRF-2016R1A5A1013277. KA also appreciates APCTP for its hospitality during completion
of this work. PO acknowledges support from the French ANR funded project ORAGE (ANR-14-CE33-0016).
ND and DA acknowledge funding from the French ANR for project ANR-12-JS05- 0001
(EMMA). The CoDa II simulation was performed at Oak Ridge National Laboratory/Oak
Ridge Leadership Computing Facility on the Titan supercomputer (INCITE 2016 award
AST031). Processing was performed on the Eos and Rhea clusters. Resolution study
simulations were performed on Piz Daint at the Swiss National Supercomputing Center
(PRACE Tier 0 award, project id pr37). The authors would like to acknowledge the
High Performance Computing center of the University of Strasbourg for supporting
this work by providing scientific support and access to computing resources. Part
of the computing resources were funded by the Equipex EquipMeso project (Programme
Investissements d’Avenir) and the CPER Alsacalcul/Big Data.
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Max
full_name: Gronke, Max
last_name: Gronke
- first_name: Pierre
full_name: Ocvirk, Pierre
last_name: Ocvirk
- first_name: Charlotte
full_name: Mason, Charlotte
last_name: Mason
- first_name: Jorryt J
full_name: Matthee, Jorryt J
id: 7439a258-f3c0-11ec-9501-9df22fe06720
last_name: Matthee
orcid: 0000-0003-2871-127X
- first_name: Sarah E I
full_name: Bosman, Sarah E I
last_name: Bosman
- first_name: Jenny G
full_name: Sorce, Jenny G
last_name: Sorce
- first_name: Joseph
full_name: Lewis, Joseph
last_name: Lewis
- first_name: Kyungjin
full_name: Ahn, Kyungjin
last_name: Ahn
- first_name: Dominique
full_name: Aubert, Dominique
last_name: Aubert
- first_name: Taha
full_name: Dawoodbhoy, Taha
last_name: Dawoodbhoy
- first_name: Ilian T
full_name: Iliev, Ilian T
last_name: Iliev
- first_name: Paul R
full_name: Shapiro, Paul R
last_name: Shapiro
- first_name: Gustavo
full_name: Yepes, Gustavo
last_name: Yepes
citation:
ama: Gronke M, Ocvirk P, Mason C, et al. Lyman-α transmission properties of the
intergalactic medium in the CoDaII simulation. Monthly Notices of the Royal
Astronomical Society. 2021;508(3):3697-3709. doi:10.1093/mnras/stab2762
apa: Gronke, M., Ocvirk, P., Mason, C., Matthee, J. J., Bosman, S. E. I., Sorce,
J. G., … Yepes, G. (2021). Lyman-α transmission properties of the intergalactic
medium in the CoDaII simulation. Monthly Notices of the Royal Astronomical
Society. Oxford University Press. https://doi.org/10.1093/mnras/stab2762
chicago: Gronke, Max, Pierre Ocvirk, Charlotte Mason, Jorryt J Matthee, Sarah E
I Bosman, Jenny G Sorce, Joseph Lewis, et al. “Lyman-α Transmission Properties
of the Intergalactic Medium in the CoDaII Simulation.” Monthly Notices of the
Royal Astronomical Society. Oxford University Press, 2021. https://doi.org/10.1093/mnras/stab2762.
ieee: M. Gronke et al., “Lyman-α transmission properties of the intergalactic
medium in the CoDaII simulation,” Monthly Notices of the Royal Astronomical
Society, vol. 508, no. 3. Oxford University Press, pp. 3697–3709, 2021.
ista: Gronke M, Ocvirk P, Mason C, Matthee JJ, Bosman SEI, Sorce JG, Lewis J, Ahn
K, Aubert D, Dawoodbhoy T, Iliev IT, Shapiro PR, Yepes G. 2021. Lyman-α transmission
properties of the intergalactic medium in the CoDaII simulation. Monthly Notices
of the Royal Astronomical Society. 508(3), 3697–3709.
mla: Gronke, Max, et al. “Lyman-α Transmission Properties of the Intergalactic Medium
in the CoDaII Simulation.” Monthly Notices of the Royal Astronomical Society,
vol. 508, no. 3, Oxford University Press, 2021, pp. 3697–709, doi:10.1093/mnras/stab2762.
short: M. Gronke, P. Ocvirk, C. Mason, J.J. Matthee, S.E.I. Bosman, J.G. Sorce,
J. Lewis, K. Ahn, D. Aubert, T. Dawoodbhoy, I.T. Iliev, P.R. Shapiro, G. Yepes,
Monthly Notices of the Royal Astronomical Society 508 (2021) 3697–3709.
date_created: 2022-07-07T09:30:21Z
date_published: 2021-12-01T00:00:00Z
date_updated: 2022-08-18T10:45:56Z
day: '01'
doi: 10.1093/mnras/stab2762
extern: '1'
external_id:
arxiv:
- '2004.14496'
intvolume: ' 508'
issue: '3'
keyword:
- dark ages
- reionization
- first stars
- intergalactic medium
- 'galaxies: formation'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/2004.14496
month: '12'
oa: 1
oa_version: Preprint
page: 3697-3709
publication: Monthly Notices of the Royal Astronomical Society
publication_identifier:
eissn:
- 1365-2966
issn:
- 0035-8711
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: Lyman-α transmission properties of the intergalactic medium in the CoDaII simulation
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 508
year: '2021'
...
---
_id: '11523'
abstract:
- lang: eng
text: We present the first results from the X-SHOOTER Lyman α survey at z = 2 (XLS-z2).
XLS-z2 is a deep spectroscopic survey of 35 Lyman α emitters (LAEs) utilizing
≈90 h of exposure time with Very Large Telescope/X-SHOOTER and covers rest-frame
Ly α to H α emission with R ≈ 4000. We present the sample selection, the observations,
and the data reduction. Systemic redshifts are measured from rest-frame optical
lines for 33/35 sources. In the stacked spectrum, our LAEs are characterized by
an interstellar medium with little dust, a low metallicity, and a high ionization
state. The ionizing sources are young hot stars that power strong emission lines
in the optical and high-ionization lines in the ultraviolet (UV). The LAEs exhibit
clumpy UV morphologies and have outflowing kinematics with blueshifted Si II absorption,
a broad [O III] component, and a red-skewed Ly α line. Typically, 30 per cent
of the Ly α photons escape, of which one quarter on the blue side of the systemic
velocity. A fraction of Ly α photons escape directly at the systemic suggesting
clear channels enabling an ≈10 per cent escape of ionizing photons, consistent
with an inference based on Mg II. A combination of a low effective H I column
density, a low dust content, and young starburst determines whether a star-forming
galaxy is observed as an LAE. The first is possibly related to outflows and/or
a fortunate viewing angle, while we find that the latter two in LAEs are typical
for their stellar mass of 109 M⊙.
acknowledgement: "We thank the referee for constructive comments and suggestions.
We thank Dawn Erb, Ruari Mackenzie, Ivan Oteo, Ryan Sanders, and Johannes Zabl for
useful discussions and suggestions. It is a pleasure to thank the ESO User Support,
in particular Giacomo Beccari, Carlo Manara, John Pritchard, Marina Rejkuba, and
Lowell Tacconi-Garman for assistance in the preparation and execution of the observations.
Based on observations obtained with the VLT, programs 084.A-0303, 088.A-0672, 091.A-0413,
091.A-0546, 092.A0774, 097.A-0153, 098.A-0819, 099.A-0758, 099.A-0254, 101.B0779,
and 102.A-0652. Based on data products from observations made with ESO Telescopes
at the La Silla Paranal Observatory under ESO programme ID 179.A-2005 and on data
products produced by CALET and the Cambridge Astronomy Survey Unit on behalf of
the UltraVISTA consortium. Based on observations made with the NASA/ESA HST through
programs 9133, 9367, 11694, and 12471, and obtained from the Hubble Legacy Archive,
which is a collaboration between the Space Telescope Science Institute (STScI/NASA),
the Space Telescope European Coordinating Facility (ST-ECF/ESA), and the Canadian
Astronomy Data Centre (CADC/NRC/CSA). This work is based on observations taken by
the CANDELS Multi-Cycle Treasury Program with the NASA/ESA HST, which is operated
by the Association of Universities for Research in Astronomy, Inc., under NASA contract
NAS5-26555. MG was supported by NASA through the NASA Hubble Fellowship grant HST-HF2-51409
and acknowledges support from HST grants\r\nHST-GO-15643.017-A, HST-AR-15039.003-A,
and XSEDE grant TG-AST180036. GP acknowledges support from the Netherlands Research
School for Astronomy (NOVA). RA acknowledges the support of ANID FONDECYT Regular
Grant 1202007. We gratefully acknowledge the PYTHON programming language, its NUMPY,
MATPLOTLIB, SCIPY, LMFIT (Jones et al. 2001; Hunter 2007; van der Walt, Colbert
& Varoquaux 2011), PANDAS (McKinney 2010), and ASTROPY (Astropy Collaboration 2013)
packages, and the TOPCAT analysis tool (Taylor 2013). Dedicated to the memory of
A. C. J.Matthee (1953–2020)."
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Jorryt J
full_name: Matthee, Jorryt J
id: 7439a258-f3c0-11ec-9501-9df22fe06720
last_name: Matthee
orcid: 0000-0003-2871-127X
- first_name: David
full_name: Sobral, David
last_name: Sobral
- first_name: Matthew
full_name: Hayes, Matthew
last_name: Hayes
- first_name: Gabriele
full_name: Pezzulli, Gabriele
last_name: Pezzulli
- first_name: Max
full_name: Gronke, Max
last_name: Gronke
- first_name: Daniel
full_name: Schaerer, Daniel
last_name: Schaerer
- first_name: Rohan P
full_name: Naidu, Rohan P
last_name: Naidu
- first_name: Huub
full_name: Röttgering, Huub
last_name: Röttgering
- first_name: João
full_name: Calhau, João
last_name: Calhau
- first_name: Ana
full_name: Paulino-Afonso, Ana
last_name: Paulino-Afonso
- first_name: Sérgio
full_name: Santos, Sérgio
last_name: Santos
- first_name: Ricardo
full_name: Amorín, Ricardo
last_name: Amorín
citation:
ama: 'Matthee JJ, Sobral D, Hayes M, et al. The X-SHOOTER Lyman α survey at z =
2 (XLS-z2) I: What makes a galaxy a Lyman α emitter? Monthly Notices of the
Royal Astronomical Society. 2021;505(1):1382-1412. doi:10.1093/mnras/stab1304'
apa: 'Matthee, J. J., Sobral, D., Hayes, M., Pezzulli, G., Gronke, M., Schaerer,
D., … Amorín, R. (2021). The X-SHOOTER Lyman α survey at z = 2 (XLS-z2) I: What
makes a galaxy a Lyman α emitter? Monthly Notices of the Royal Astronomical
Society. Oxford University Press. https://doi.org/10.1093/mnras/stab1304'
chicago: 'Matthee, Jorryt J, David Sobral, Matthew Hayes, Gabriele Pezzulli, Max
Gronke, Daniel Schaerer, Rohan P Naidu, et al. “The X-SHOOTER Lyman α Survey at
z = 2 (XLS-Z2) I: What Makes a Galaxy a Lyman α Emitter?” Monthly Notices of
the Royal Astronomical Society. Oxford University Press, 2021. https://doi.org/10.1093/mnras/stab1304.'
ieee: 'J. J. Matthee et al., “The X-SHOOTER Lyman α survey at z = 2 (XLS-z2)
I: What makes a galaxy a Lyman α emitter?,” Monthly Notices of the Royal Astronomical
Society, vol. 505, no. 1. Oxford University Press, pp. 1382–1412, 2021.'
ista: 'Matthee JJ, Sobral D, Hayes M, Pezzulli G, Gronke M, Schaerer D, Naidu RP,
Röttgering H, Calhau J, Paulino-Afonso A, Santos S, Amorín R. 2021. The X-SHOOTER
Lyman α survey at z = 2 (XLS-z2) I: What makes a galaxy a Lyman α emitter? Monthly
Notices of the Royal Astronomical Society. 505(1), 1382–1412.'
mla: 'Matthee, Jorryt J., et al. “The X-SHOOTER Lyman α Survey at z = 2 (XLS-Z2)
I: What Makes a Galaxy a Lyman α Emitter?” Monthly Notices of the Royal Astronomical
Society, vol. 505, no. 1, Oxford University Press, 2021, pp. 1382–412, doi:10.1093/mnras/stab1304.'
short: J.J. Matthee, D. Sobral, M. Hayes, G. Pezzulli, M. Gronke, D. Schaerer, R.P.
Naidu, H. Röttgering, J. Calhau, A. Paulino-Afonso, S. Santos, R. Amorín, Monthly
Notices of the Royal Astronomical Society 505 (2021) 1382–1412.
date_created: 2022-07-07T09:33:39Z
date_published: 2021-07-01T00:00:00Z
date_updated: 2022-08-18T10:49:00Z
day: '01'
doi: 10.1093/mnras/stab1304
extern: '1'
external_id:
arxiv:
- '2102.07779'
intvolume: ' 505'
issue: '1'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- 'galaxies: formation'
- 'galaxies: ISM'
- 'galaxies: starburst'
- dark ages
- reionization
- first stars
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/2102.07779
month: '07'
oa: 1
oa_version: Preprint
page: 1382-1412
publication: Monthly Notices of the Royal Astronomical Society
publication_identifier:
eissn:
- 1365-2966
issn:
- 0035-8711
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'The X-SHOOTER Lyman α survey at z = 2 (XLS-z2) I: What makes a galaxy a Lyman
α emitter?'
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 505
year: '2021'
...
---
_id: '11605'
abstract:
- lang: eng
text: "Context. The discovery of moderate differential rotation between the core
and the envelope of evolved solar-like stars could be the signature of a strong
magnetic field trapped inside the radiative interior. The population of intermediate-mass
red giants presenting surprisingly low-amplitude mixed modes (i.e. oscillation
modes that behave as acoustic modes in their external envelope and as gravity
modes in their core) could also arise from the effect of an internal magnetic
field. Indeed, stars more massive than about 1.1 solar masses are known to develop
a convective core during their main sequence. The field generated by the dynamo
triggered by this convection could be the progenitor of a strong fossil magnetic
field trapped inside the core of the star for the remainder of its evolution.\r\n\r\nAims.
Observations of mixed modes can constitute an excellent probe of the deepest layers
of evolved solar-like stars, and magnetic fields in those regions can impact their
propagation. The magnetic perturbation on mixed modes may therefore be visible
in asteroseismic data. To unravel which constraints can be obtained from observations,
we theoretically investigate the effects of a plausible mixed axisymmetric magnetic
field with various amplitudes on the mixed-mode frequencies of evolved solar-like
stars.\r\n\r\nMethods. First-order frequency perturbations due to an axisymmetric
magnetic field were computed for dipolar and quadrupolar mixed modes. These computations
were carried out for a range of stellar ages, masses, and metallicities.\r\n\r\nConclusions.
We show that typical fossil-field strengths of 0.1 − 1 MG, consistent with the
presence of a dynamo in the convective core during the main sequence, provoke
significant asymmetries on mixed-mode frequency multiplets during the red giant
branch. We provide constraints and methods for the detectability of such magnetic
signatures. We show that these signatures may be detectable in asteroseismic data
for field amplitudes small enough for the amplitude of the modes not to be affected
by the conversion of gravity into Alfvén waves inside the magnetised interior.
Finally, we infer an upper limit for the strength of the field and the associated
lower limit for the timescale of its action in order to redistribute angular momentum
in stellar interiors."
article_number: A53
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Lisa Annabelle
full_name: Bugnet, Lisa Annabelle
id: d9edb345-f866-11ec-9b37-d119b5234501
last_name: Bugnet
orcid: 0000-0003-0142-4000
- first_name: V.
full_name: Prat, V.
last_name: Prat
- first_name: S.
full_name: Mathis, S.
last_name: Mathis
- first_name: A.
full_name: Astoul, A.
last_name: Astoul
- first_name: K.
full_name: Augustson, K.
last_name: Augustson
- first_name: R. A.
full_name: García, R. A.
last_name: García
- first_name: S.
full_name: Mathur, S.
last_name: Mathur
- first_name: L.
full_name: Amard, L.
last_name: Amard
- first_name: C.
full_name: Neiner, C.
last_name: Neiner
citation:
ama: 'Bugnet LA, Prat V, Mathis S, et al. Magnetic signatures on mixed-mode frequencies:
I. An axisymmetric fossil field inside the core of red giants. Astronomy &
Astrophysics. 2021;650. doi:10.1051/0004-6361/202039159'
apa: 'Bugnet, L. A., Prat, V., Mathis, S., Astoul, A., Augustson, K., García, R.
A., … Neiner, C. (2021). Magnetic signatures on mixed-mode frequencies: I. An
axisymmetric fossil field inside the core of red giants. Astronomy & Astrophysics.
EDP Sciences. https://doi.org/10.1051/0004-6361/202039159'
chicago: 'Bugnet, Lisa Annabelle, V. Prat, S. Mathis, A. Astoul, K. Augustson, R.
A. García, S. Mathur, L. Amard, and C. Neiner. “Magnetic Signatures on Mixed-Mode
Frequencies: I. An Axisymmetric Fossil Field inside the Core of Red Giants.” Astronomy
& Astrophysics. EDP Sciences, 2021. https://doi.org/10.1051/0004-6361/202039159.'
ieee: 'L. A. Bugnet et al., “Magnetic signatures on mixed-mode frequencies:
I. An axisymmetric fossil field inside the core of red giants,” Astronomy &
Astrophysics, vol. 650. EDP Sciences, 2021.'
ista: 'Bugnet LA, Prat V, Mathis S, Astoul A, Augustson K, García RA, Mathur S,
Amard L, Neiner C. 2021. Magnetic signatures on mixed-mode frequencies: I. An
axisymmetric fossil field inside the core of red giants. Astronomy & Astrophysics.
650, A53.'
mla: 'Bugnet, Lisa Annabelle, et al. “Magnetic Signatures on Mixed-Mode Frequencies:
I. An Axisymmetric Fossil Field inside the Core of Red Giants.” Astronomy &
Astrophysics, vol. 650, A53, EDP Sciences, 2021, doi:10.1051/0004-6361/202039159.'
short: L.A. Bugnet, V. Prat, S. Mathis, A. Astoul, K. Augustson, R.A. García, S.
Mathur, L. Amard, C. Neiner, Astronomy & Astrophysics 650 (2021).
date_created: 2022-07-18T12:10:59Z
date_published: 2021-06-07T00:00:00Z
date_updated: 2022-08-19T10:06:33Z
day: '07'
doi: 10.1051/0004-6361/202039159
extern: '1'
external_id:
arxiv:
- '2102.01216'
intvolume: ' 650'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- stars
- oscillations / stars
- magnetic field / stars
- interiors / stars
- evolution / stars
- rotation
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/2102.01216
month: '06'
oa: 1
oa_version: Preprint
publication: Astronomy & Astrophysics
publication_identifier:
eissn:
- 1432-0746
issn:
- 0004-6361
publication_status: published
publisher: EDP Sciences
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Magnetic signatures on mixed-mode frequencies: I. An axisymmetric fossil field
inside the core of red giants'
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 650
year: '2021'
...
---
_id: '11606'
abstract:
- lang: eng
text: "Context. Our knowledge of the dynamics of stars has undergone a revolution
through the simultaneous large amount of high-quality photometric observations
collected by space-based asteroseismology and ground-based high-precision spectropolarimetry.
They allowed us to probe the internal rotation of stars and their surface magnetism
in the whole Hertzsprung-Russell diagram. However, new methods should still be
developed to probe the deep magnetic fields in these stars.\r\n\r\nAims. Our goal
is to provide seismic diagnoses that allow us to probe the internal magnetism
of stars.\r\n\r\nMethods. We focused on asymptotic low-frequency gravity modes
and high-frequency acoustic modes. Using a first-order perturbative theory, we
derived magnetic splittings of their frequencies as explicit functions of stellar
parameters.\r\n\r\nResults. As in the case of rotation, we show that asymptotic
gravity and acoustic modes can allow us to probe the different components of the
magnetic field in the cavities in which they propagate. This again demonstrates
the high potential of using mixed-modes when this is possible."
acknowledgement: The authors thank the referee and Pr. J. Christensen-Dalsgaard for
their very constructive comments and remarks that allowed us to improve the article.
St. M., L. B., V. P., and K. A. acknowledge support from the European Research Council
through ERC grant SPIRE 647383. All the members from CEA acknowledge support from
GOLF and PLATO CNES grants of the Astrophysics Division at CEA. S. Mathur acknowledges
support by the Ramon y Cajal fellowship number RYC-2015-17697. We made great use
of the megyr python package for interfacing MESA and GYRE codes.
article_number: A122
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: S.
full_name: Mathis, S.
last_name: Mathis
- first_name: Lisa Annabelle
full_name: Bugnet, Lisa Annabelle
id: d9edb345-f866-11ec-9b37-d119b5234501
last_name: Bugnet
orcid: 0000-0003-0142-4000
- first_name: V.
full_name: Prat, V.
last_name: Prat
- first_name: K.
full_name: Augustson, K.
last_name: Augustson
- first_name: S.
full_name: Mathur, S.
last_name: Mathur
- first_name: R. A.
full_name: Garcia, R. A.
last_name: Garcia
citation:
ama: Mathis S, Bugnet LA, Prat V, Augustson K, Mathur S, Garcia RA. Probing the
internal magnetism of stars using asymptotic magneto-asteroseismology. Astronomy
& Astrophysics. 2021;647. doi:10.1051/0004-6361/202039180
apa: Mathis, S., Bugnet, L. A., Prat, V., Augustson, K., Mathur, S., & Garcia,
R. A. (2021). Probing the internal magnetism of stars using asymptotic magneto-asteroseismology.
Astronomy & Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/202039180
chicago: Mathis, S., Lisa Annabelle Bugnet, V. Prat, K. Augustson, S. Mathur, and
R. A. Garcia. “Probing the Internal Magnetism of Stars Using Asymptotic Magneto-Asteroseismology.”
Astronomy & Astrophysics. EDP Sciences, 2021. https://doi.org/10.1051/0004-6361/202039180.
ieee: S. Mathis, L. A. Bugnet, V. Prat, K. Augustson, S. Mathur, and R. A. Garcia,
“Probing the internal magnetism of stars using asymptotic magneto-asteroseismology,”
Astronomy & Astrophysics, vol. 647. EDP Sciences, 2021.
ista: Mathis S, Bugnet LA, Prat V, Augustson K, Mathur S, Garcia RA. 2021. Probing
the internal magnetism of stars using asymptotic magneto-asteroseismology. Astronomy
& Astrophysics. 647, A122.
mla: Mathis, S., et al. “Probing the Internal Magnetism of Stars Using Asymptotic
Magneto-Asteroseismology.” Astronomy & Astrophysics, vol. 647, A122,
EDP Sciences, 2021, doi:10.1051/0004-6361/202039180.
short: S. Mathis, L.A. Bugnet, V. Prat, K. Augustson, S. Mathur, R.A. Garcia, Astronomy
& Astrophysics 647 (2021).
date_created: 2022-07-18T12:15:27Z
date_published: 2021-03-18T00:00:00Z
date_updated: 2022-08-19T10:11:52Z
day: '18'
doi: 10.1051/0004-6361/202039180
extern: '1'
external_id:
arxiv:
- '2012.11050'
intvolume: ' 647'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- asteroseismology / waves / stars
- magnetic field / stars
- oscillations / methods
- analytical
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/2012.11050
month: '03'
oa: 1
oa_version: Preprint
publication: Astronomy & Astrophysics
publication_identifier:
eissn:
- 1432-0746
issn:
- 0004-6361
publication_status: published
publisher: EDP Sciences
quality_controlled: '1'
scopus_import: '1'
status: public
title: Probing the internal magnetism of stars using asymptotic magneto-asteroseismology
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 647
year: '2021'
...
---
_id: '11608'
abstract:
- lang: eng
text: 'In order to understand stellar evolution, it is crucial to efficiently determine
stellar surface rotation periods. Indeed, while they are of great importance in
stellar models, angular momentum transport processes inside stars are still poorly
understood today. Surface rotation, which is linked to the age of the star, is
one of the constraints needed to improve the way those processes are modelled.
Statistics of the surface rotation periods for a large sample of stars of different
spectral types are thus necessary. An efficient tool to automatically determine
reliable rotation periods is needed when dealing with large samples of stellar
photometric datasets. The objective of this work is to develop such a tool. For
this purpose, machine learning classifiers constitute relevant bases to build
our new methodology. Random forest learning abilities are exploited to automate
the extraction of rotation periods in Kepler light curves. Rotation periods and
complementary parameters are obtained via three different methods: a wavelet analysis,
the autocorrelation function of the light curve, and the composite spectrum. We
trained three different classifiers: one to detect if rotational modulations are
present in the light curve, one to flag close binary or classical pulsators candidates
that can bias our rotation period determination, and finally one classifier to
provide the final rotation period. We tested our machine learning pipeline on
23 431 stars of the Kepler K and M dwarf reference rotation catalogue for which
60% of the stars have been visually inspected. For the sample of 21 707 stars
where all the input parameters are provided to the algorithm, 94.2% of them are
correctly classified (as rotating or not). Among the stars that have a rotation
period in the reference catalogue, the machine learning provides a period that
agrees within 10% of the reference value for 95.3% of the stars. Moreover, the
yield of correct rotation periods is raised to 99.5% after visually inspecting
25.2% of the stars. Over the two main analysis steps, rotation classification
and period selection, the pipeline yields a global agreement with the reference
values of 92.1% and 96.9% before and after visual inspection. Random forest classifiers
are efficient tools to determine reliable rotation periods in large samples of
stars. The methodology presented here could be easily adapted to extract surface
rotation periods for stars with different spectral types or observed by other
instruments such as K2, TESS or by PLATO in the near future.'
acknowledgement: 'We thank Suzanne Aigrain and Joe Llama for providing us with the
simulated data used in Aigrain et al. (2015). S. N. B., L. B. and R. A. G. acknowledge
the support from PLATO and GOLF CNES grants. A. R. G. S. acknowledges the support
from NASA under grant NNX17AF27G. S. M. acknowledges the support from the Spanish
Ministry of Science and Innovation with the Ramon y Cajal fellowship number RYC-2015-17697.
P. L. P. and S. M. acknowledge support from the Spanish Ministry of Science and
Innovation with the grant number PID2019-107187GB-I00. This research has made use
of the NASA Exoplanet Archive, which is operated by the California Institute of
Technology, under contract with the National Aeronautics and Space Administration
under the Exoplanet Exploration Program. Software: Python (Van Rossum & Drake 2009),
numpy (Oliphant 2006), pandas (The pandas development team 2020; McKinney 2010),
matplotlib (Hunter 2007), scikit-learn (Pedregosa et al. 2011). The source code
used to obtain the present results can be found at: https://gitlab.com/sybreton/pushkin
; https://gitlab.com/sybreton/ml_surface_rotation_paper .'
article_number: A125
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: S. N.
full_name: Breton, S. N.
last_name: Breton
- first_name: A. R. G.
full_name: Santos, A. R. G.
last_name: Santos
- first_name: Lisa Annabelle
full_name: Bugnet, Lisa Annabelle
id: d9edb345-f866-11ec-9b37-d119b5234501
last_name: Bugnet
orcid: 0000-0003-0142-4000
- first_name: S.
full_name: Mathur, S.
last_name: Mathur
- first_name: R. A.
full_name: García, R. A.
last_name: García
- first_name: P. L.
full_name: Pallé, P. L.
last_name: Pallé
citation:
ama: 'Breton SN, Santos ARG, Bugnet LA, Mathur S, García RA, Pallé PL. ROOSTER:
A machine-learning analysis tool for Kepler stellar rotation periods. Astronomy
& Astrophysics. 2021;647. doi:10.1051/0004-6361/202039947'
apa: 'Breton, S. N., Santos, A. R. G., Bugnet, L. A., Mathur, S., García, R. A.,
& Pallé, P. L. (2021). ROOSTER: A machine-learning analysis tool for Kepler
stellar rotation periods. Astronomy & Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/202039947'
chicago: 'Breton, S. N., A. R. G. Santos, Lisa Annabelle Bugnet, S. Mathur, R. A.
García, and P. L. Pallé. “ROOSTER: A Machine-Learning Analysis Tool for Kepler
Stellar Rotation Periods.” Astronomy & Astrophysics. EDP Sciences,
2021. https://doi.org/10.1051/0004-6361/202039947.'
ieee: 'S. N. Breton, A. R. G. Santos, L. A. Bugnet, S. Mathur, R. A. García, and
P. L. Pallé, “ROOSTER: A machine-learning analysis tool for Kepler stellar rotation
periods,” Astronomy & Astrophysics, vol. 647. EDP Sciences, 2021.'
ista: 'Breton SN, Santos ARG, Bugnet LA, Mathur S, García RA, Pallé PL. 2021. ROOSTER:
A machine-learning analysis tool for Kepler stellar rotation periods. Astronomy
& Astrophysics. 647, A125.'
mla: 'Breton, S. N., et al. “ROOSTER: A Machine-Learning Analysis Tool for Kepler
Stellar Rotation Periods.” Astronomy & Astrophysics, vol. 647, A125,
EDP Sciences, 2021, doi:10.1051/0004-6361/202039947.'
short: S.N. Breton, A.R.G. Santos, L.A. Bugnet, S. Mathur, R.A. García, P.L. Pallé,
Astronomy & Astrophysics 647 (2021).
date_created: 2022-07-18T12:21:32Z
date_published: 2021-03-19T00:00:00Z
date_updated: 2022-08-22T08:47:47Z
day: '19'
doi: 10.1051/0004-6361/202039947
extern: '1'
external_id:
arxiv:
- '2101.10152'
intvolume: ' 647'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- 'methods: data analysis / stars: solar-type / stars: activity / stars: rotation
/ starspots'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/2101.10152
month: '03'
oa: 1
oa_version: Preprint
publication: Astronomy & Astrophysics
publication_identifier:
eissn:
- 1432-0746
issn:
- 0004-6361
publication_status: published
publisher: EDP Sciences
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'ROOSTER: A machine-learning analysis tool for Kepler stellar rotation periods'
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 647
year: '2021'
...
---
_id: '11609'
abstract:
- lang: eng
text: "Context. Stellar interiors are the seat of efficient transport of angular
momentum all along their evolution. In this context, understanding the dependence
of the turbulent transport triggered by the instabilities of the vertical and
horizontal shears of the differential rotation in stellar radiation zones as a
function of their rotation, stratification, and thermal diffusivity is mandatory.
Indeed, it constitutes one of the cornerstones of the rotational transport and
mixing theory, which is implemented in stellar evolution codes to predict the
rotational and chemical evolutions of stars.\r\n\r\nAims. We investigate horizontal
shear instabilities in rotating stellar radiation zones by considering the full
Coriolis acceleration with both the dimensionless horizontal Coriolis component
f̃ and the vertical component f.\r\n\r\nMethods. We performed a linear stability
analysis using linearized equations derived from the Navier-Stokes and heat transport
equations in the rotating nontraditional f-plane. We considered a horizontal shear
flow with a hyperbolic tangent profile as the base flow. The linear stability
was analyzed numerically in wide ranges of parameters, and we performed an asymptotic
analysis for large vertical wavenumbers using the Wentzel-Kramers-Brillouin-Jeffreys
(WKBJ) approximation for nondiffusive and highly-diffusive fluids.\r\n\r\nResults.
As in the traditional f-plane approximation, we identify two types of instabilities:
the inflectional and inertial instabilities. The inflectional instability is destabilized
as f̃ increases and its maximum growth rate increases significantly, while the
thermal diffusivity stabilizes the inflectional instability similarly to the traditional
case. The inertial instability is also strongly affected; for instance, the inertially
unstable regime is also extended in the nondiffusive limit as 0 < f < 1 + f̃ 2/N2,
where N is the dimensionless Brunt-Väisälä frequency. More strikingly, in the
high thermal diffusivity limit, it is always inertially unstable at any colatitude
θ except at the poles (i.e., 0° < θ < 180°). We also derived the critical Reynolds
numbers for the inertial instability using the asymptotic dispersion relations
obtained from the WKBJ analysis. Using the asymptotic and numerical results, we
propose a prescription for the effective turbulent viscosities induced by the
inertial and inflectional instabilities that can be possibly used in stellar evolution
models. The characteristic time of this turbulence is short enough so that it
is efficient to redistribute angular momentum and to mix chemicals in stellar
radiation zones."
acknowledgement: The authors acknowledge support from the European Research Council
through ERC grant SPIRE 647383 and from GOLF and PLATO CNES grants at the Department
of Astrophysics at CEA Paris-Saclay. We thank the referee, Prof. A. J. Barker, for
his constructive comments that allow us to improve the article.
article_number: A64
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: J.
full_name: Park, J.
last_name: Park
- first_name: V.
full_name: Prat, V.
last_name: Prat
- first_name: S.
full_name: Mathis, S.
last_name: Mathis
- first_name: Lisa Annabelle
full_name: Bugnet, Lisa Annabelle
id: d9edb345-f866-11ec-9b37-d119b5234501
last_name: Bugnet
orcid: 0000-0003-0142-4000
citation:
ama: 'Park J, Prat V, Mathis S, Bugnet LA. Horizontal shear instabilities in rotating
stellar radiation zones: II. Effects of the full Coriolis acceleration. Astronomy
& Astrophysics. 2021;646. doi:10.1051/0004-6361/202038654'
apa: 'Park, J., Prat, V., Mathis, S., & Bugnet, L. A. (2021). Horizontal shear
instabilities in rotating stellar radiation zones: II. Effects of the full Coriolis
acceleration. Astronomy & Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/202038654'
chicago: 'Park, J., V. Prat, S. Mathis, and Lisa Annabelle Bugnet. “Horizontal Shear
Instabilities in Rotating Stellar Radiation Zones: II. Effects of the Full Coriolis
Acceleration.” Astronomy & Astrophysics. EDP Sciences, 2021. https://doi.org/10.1051/0004-6361/202038654.'
ieee: 'J. Park, V. Prat, S. Mathis, and L. A. Bugnet, “Horizontal shear instabilities
in rotating stellar radiation zones: II. Effects of the full Coriolis acceleration,”
Astronomy & Astrophysics, vol. 646. EDP Sciences, 2021.'
ista: 'Park J, Prat V, Mathis S, Bugnet LA. 2021. Horizontal shear instabilities
in rotating stellar radiation zones: II. Effects of the full Coriolis acceleration.
Astronomy & Astrophysics. 646, A64.'
mla: 'Park, J., et al. “Horizontal Shear Instabilities in Rotating Stellar Radiation
Zones: II. Effects of the Full Coriolis Acceleration.” Astronomy & Astrophysics,
vol. 646, A64, EDP Sciences, 2021, doi:10.1051/0004-6361/202038654.'
short: J. Park, V. Prat, S. Mathis, L.A. Bugnet, Astronomy & Astrophysics 646
(2021).
date_created: 2022-07-18T13:24:32Z
date_published: 2021-02-08T00:00:00Z
date_updated: 2022-08-19T10:18:03Z
day: '08'
doi: 10.1051/0004-6361/202038654
extern: '1'
external_id:
arxiv:
- '2006.10660'
intvolume: ' 646'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- hydrodynamics / turbulence / stars
- rotation / stars
- evolution
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/2006.10660
month: '02'
oa: 1
oa_version: Preprint
publication: Astronomy & Astrophysics
publication_identifier:
eissn:
- 1432-0746
issn:
- 0004-6361
publication_status: published
publisher: EDP Sciences
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Horizontal shear instabilities in rotating stellar radiation zones: II. Effects
of the full Coriolis acceleration'
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 646
year: '2021'
...
---
_id: '11503'
abstract:
- lang: eng
text: "Context. The Lyα emitter (LAE) fraction, XLAE, is a potentially powerful
probe of the evolution of the intergalactic neutral hydrogen gas fraction. However,
uncertainties in the measurement of XLAE are still under debate.\r\nAims. Thanks
to deep data obtained with the integral field spectrograph Multi Unit Spectroscopic
Explorer (MUSE), we can measure the evolution of the LAE fraction homogeneously
over a wide redshift range of z ≈ 3–6 for UV-faint galaxies (down to UV magnitudes
of M1500 ≈ −17.75). This is a significantly fainter range than in former studies
(M1500 ≤ −18.75) and it allows us to probe the bulk of the population of high-redshift
star-forming galaxies.\r\nMethods. We constructed a UV-complete photometric-redshift
sample following UV luminosity functions and measured the Lyα emission with MUSE
using the latest (second) data release from the MUSE Hubble Ultra Deep Field Survey.\r\nResults.
We derived the redshift evolution of XLAE for M1500 ∈ [ − 21.75; −17.75] for the
first time with a equivalent width range EW(Lyα) ≥ 65 Å and found low values of
XLAE ≲ 30% at z ≲ 6. The best-fit linear relation is XLAE = 0.07+0.06−0.03z −
0.22+0.12−0.24. For M1500 ∈ [ − 20.25; −18.75] and EW(Lyα) ≥ 25 Å, our XLAE values
are consistent with those in the literature within 1σ at z ≲ 5, but our median
values are systematically lower than reported values over the whole redshift range.
In addition, we do not find a significant dependence of XLAE on M1500 for EW(Lyα)
≥ 50 Å at z ≈ 3–4, in contrast with previous work. The differences in XLAE mainly
arise from selection biases for Lyman Break Galaxies (LBGs) in the literature:
UV-faint LBGs are more easily selected if they have strong Lyα emission, hence
XLAE is biased towards higher values when those samples are used.\r\nConclusions.
Our results suggest either a lower increase of XLAE towards z ≈ 6 than previously
suggested, or even a turnover of XLAE at z ≈ 5.5, which may be the signature of
a late or patchy reionization process. We compared our results with predictions
from a cosmological galaxy evolution model. We find that a model with a bursty
star formation (SF) can reproduce our observed LAE fractions much better than
models where SF is a smooth function of time."
acknowledgement: We thank the anonymous referee for constructive comments and suggestions.
We would like to express our gratitude to Stephane De Barros and Pablo Arrabal Haro
for kindly providing their data plotted in Figs. 1, 2, and 8. We are grateful to
Kazuhiro Shimasaku, Masami Ouchi, Rieko Momose, Daniel Schaerer, Hidenobu Yajima,
Taku Okamura, Makoto Ando, and Hinako Goto for giving insightful comments and suggestions.
This work is based on observations taken by VLT, which is operated by European Southern
Observatory. This research made use of Astropy (http://www.astropy.org), which is
a community-developed core Python package for Astronomy (Astropy Collaboration 2013,
2018), MARZ, MPDAF, and matplotlib (Hunter 2007). H.K. acknowledges support from
Japan Society for the Promotion of Science (JSPS) through the JSPS Research Fellowship
for Young Scientists and Overseas Challenge Program for Young Researchers. AV acknowledges
support from the ERC starting grant 757258-TRIPLE and the SNF Professorship 176808-TRIPLE.
This work was supported by the project FOGHAR (Agence Nationale de la Recherche,
ANR-13-BS05-0010-02). JB acknowledges support from the ORAGE project from the Agence
Nationale de la Recherche under grant ANR-14-CE33-0016-03. JR acknowledges support
from the ERC starting grant 336736-CALENDS. T. H. acknowledges supports by the Grant-inAid
for Scientic Research 19J01620.
article_number: A12
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Haruka
full_name: Kusakabe, Haruka
last_name: Kusakabe
- first_name: Jérémy
full_name: Blaizot, Jérémy
last_name: Blaizot
- first_name: Thibault
full_name: Garel, Thibault
last_name: Garel
- first_name: Anne
full_name: Verhamme, Anne
last_name: Verhamme
- first_name: Roland
full_name: Bacon, Roland
last_name: Bacon
- first_name: Johan
full_name: Richard, Johan
last_name: Richard
- first_name: Takuya
full_name: Hashimoto, Takuya
last_name: Hashimoto
- first_name: Hanae
full_name: Inami, Hanae
last_name: Inami
- first_name: Simon
full_name: Conseil, Simon
last_name: Conseil
- first_name: Bruno
full_name: Guiderdoni, Bruno
last_name: Guiderdoni
- first_name: Alyssa B.
full_name: Drake, Alyssa B.
last_name: Drake
- first_name: Edmund
full_name: Christian Herenz, Edmund
last_name: Christian Herenz
- first_name: Joop
full_name: Schaye, Joop
last_name: Schaye
- first_name: Pascal
full_name: Oesch, Pascal
last_name: Oesch
- first_name: Jorryt J
full_name: Matthee, Jorryt J
id: 7439a258-f3c0-11ec-9501-9df22fe06720
last_name: Matthee
orcid: 0000-0003-2871-127X
- first_name: Raffaella
full_name: Anna Marino, Raffaella
last_name: Anna Marino
- first_name: Kasper
full_name: Borello Schmidt, Kasper
last_name: Borello Schmidt
- first_name: Roser
full_name: Pelló, Roser
last_name: Pelló
- first_name: Michael
full_name: Maseda, Michael
last_name: Maseda
- first_name: Floriane
full_name: Leclercq, Floriane
last_name: Leclercq
- first_name: Josephine
full_name: Kerutt, Josephine
last_name: Kerutt
- first_name: Guillaume
full_name: Mahler, Guillaume
last_name: Mahler
citation:
ama: 'Kusakabe H, Blaizot J, Garel T, et al. The MUSE Hubble Ultra Deep Field Survey:
XIV. Evolution of the Lyα emitter fraction from z = 3 to z = 6. Astronomy &
Astrophysics. 2020;638. doi:10.1051/0004-6361/201937340'
apa: 'Kusakabe, H., Blaizot, J., Garel, T., Verhamme, A., Bacon, R., Richard, J.,
… Mahler, G. (2020). The MUSE Hubble Ultra Deep Field Survey: XIV. Evolution of
the Lyα emitter fraction from z = 3 to z = 6. Astronomy & Astrophysics.
EDP Sciences. https://doi.org/10.1051/0004-6361/201937340'
chicago: 'Kusakabe, Haruka, Jérémy Blaizot, Thibault Garel, Anne Verhamme, Roland
Bacon, Johan Richard, Takuya Hashimoto, et al. “The MUSE Hubble Ultra Deep Field
Survey: XIV. Evolution of the Lyα Emitter Fraction from z = 3 to z = 6.” Astronomy
& Astrophysics. EDP Sciences, 2020. https://doi.org/10.1051/0004-6361/201937340.'
ieee: 'H. Kusakabe et al., “The MUSE Hubble Ultra Deep Field Survey: XIV.
Evolution of the Lyα emitter fraction from z = 3 to z = 6,” Astronomy &
Astrophysics, vol. 638. EDP Sciences, 2020.'
ista: 'Kusakabe H, Blaizot J, Garel T, Verhamme A, Bacon R, Richard J, Hashimoto
T, Inami H, Conseil S, Guiderdoni B, Drake AB, Christian Herenz E, Schaye J, Oesch
P, Matthee JJ, Anna Marino R, Borello Schmidt K, Pelló R, Maseda M, Leclercq F,
Kerutt J, Mahler G. 2020. The MUSE Hubble Ultra Deep Field Survey: XIV. Evolution
of the Lyα emitter fraction from z = 3 to z = 6. Astronomy & Astrophysics.
638, A12.'
mla: 'Kusakabe, Haruka, et al. “The MUSE Hubble Ultra Deep Field Survey: XIV. Evolution
of the Lyα Emitter Fraction from z = 3 to z = 6.” Astronomy & Astrophysics,
vol. 638, A12, EDP Sciences, 2020, doi:10.1051/0004-6361/201937340.'
short: H. Kusakabe, J. Blaizot, T. Garel, A. Verhamme, R. Bacon, J. Richard, T.
Hashimoto, H. Inami, S. Conseil, B. Guiderdoni, A.B. Drake, E. Christian Herenz,
J. Schaye, P. Oesch, J.J. Matthee, R. Anna Marino, K. Borello Schmidt, R. Pelló,
M. Maseda, F. Leclercq, J. Kerutt, G. Mahler, Astronomy & Astrophysics 638
(2020).
date_created: 2022-07-06T09:50:48Z
date_published: 2020-06-03T00:00:00Z
date_updated: 2022-07-19T09:35:20Z
day: '03'
doi: 10.1051/0004-6361/201937340
extern: '1'
external_id:
arxiv:
- '2003.12083'
intvolume: ' 638'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- 'dark ages / reionization / first stars / early Universe / cosmology: observations
/ galaxies: evolution / galaxies: high-redshift / intergalactic medium'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/2003.12083
month: '06'
oa: 1
oa_version: Published Version
publication: Astronomy & Astrophysics
publication_identifier:
eissn:
- 1432-0746
issn:
- 0004-6361
publication_status: published
publisher: EDP Sciences
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'The MUSE Hubble Ultra Deep Field Survey: XIV. Evolution of the Lyα emitter
fraction from z = 3 to z = 6'
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 638
year: '2020'
...
---
_id: '11529'
abstract:
- lang: eng
text: CR7 is among the most luminous Ly α emitters (LAEs) known at z = 6.6 and consists
of at least three UV components that are surrounded by Ly α emission. Previous
studies have suggested that it may host an extreme ionizing source. Here, we present
deep integral field spectroscopy of CR7 with VLT/Multi Unit Spectroscopic Explorer
(MUSE). We measure extended emission with a similar halo scale length as typical
LAEs at z ≈ 5. CR7’s Ly α halo is clearly elongated along the direction connecting
the multiple components, likely tracing the underlying gas distribution. The Ly α
emission originates almost exclusively from the brightest UV component, but we
also identify a faint kinematically distinct Ly α emitting region nearby a fainter
component. Combined with new near-infrared data, the MUSE data show that the rest-frame
Ly α equivalent width (EW) is ≈100 Å. This is a factor 4 higher than the EW measured
in low-redshift analogues with carefully matched Ly α profiles (and thus arguably
H I column density), but this EW can plausibly be explained by star formation.
Alternative scenarios requiring active galactic nucleus (AGN) powering are also
disfavoured by the narrower and steeper Ly α spectrum and much smaller IR to UV
ratio compared to obscured AGN in other Ly α blobs. CR7’s Ly α emission, while
extremely luminous, resembles the emission in more common LAEs at lower redshifts
very well and is likely powered by a young metal-poor starburst.
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Jorryt J
full_name: Matthee, Jorryt J
id: 7439a258-f3c0-11ec-9501-9df22fe06720
last_name: Matthee
orcid: 0000-0003-2871-127X
- first_name: Gabriele
full_name: Pezzulli, Gabriele
last_name: Pezzulli
- first_name: Ruari
full_name: Mackenzie, Ruari
last_name: Mackenzie
- first_name: Sebastiano
full_name: Cantalupo, Sebastiano
last_name: Cantalupo
- first_name: Haruka
full_name: Kusakabe, Haruka
last_name: Kusakabe
- first_name: Floriane
full_name: Leclercq, Floriane
last_name: Leclercq
- first_name: David
full_name: Sobral, David
last_name: Sobral
- first_name: Johan
full_name: Richard, Johan
last_name: Richard
- first_name: Lutz
full_name: Wisotzki, Lutz
last_name: Wisotzki
- first_name: Simon
full_name: Lilly, Simon
last_name: Lilly
- first_name: Leindert
full_name: Boogaard, Leindert
last_name: Boogaard
- first_name: Raffaella
full_name: Marino, Raffaella
last_name: Marino
- first_name: Michael
full_name: Maseda, Michael
last_name: Maseda
- first_name: Themiya
full_name: Nanayakkara, Themiya
last_name: Nanayakkara
citation:
ama: 'Matthee JJ, Pezzulli G, Mackenzie R, et al. The nature of CR7 revealed with
MUSE: A young starburst powering extended Ly α emission at z = 6.6. Monthly
Notices of the Royal Astronomical Society. 2020;498(2):3043-3059. doi:10.1093/mnras/staa2550'
apa: 'Matthee, J. J., Pezzulli, G., Mackenzie, R., Cantalupo, S., Kusakabe, H.,
Leclercq, F., … Nanayakkara, T. (2020). The nature of CR7 revealed with MUSE:
A young starburst powering extended Ly α emission at z = 6.6. Monthly Notices
of the Royal Astronomical Society. Oxford University Press. https://doi.org/10.1093/mnras/staa2550'
chicago: 'Matthee, Jorryt J, Gabriele Pezzulli, Ruari Mackenzie, Sebastiano Cantalupo,
Haruka Kusakabe, Floriane Leclercq, David Sobral, et al. “The Nature of CR7 Revealed
with MUSE: A Young Starburst Powering Extended Ly α Emission at z = 6.6.” Monthly
Notices of the Royal Astronomical Society. Oxford University Press, 2020.
https://doi.org/10.1093/mnras/staa2550.'
ieee: 'J. J. Matthee et al., “The nature of CR7 revealed with MUSE: A young
starburst powering extended Ly α emission at z = 6.6,” Monthly Notices of the
Royal Astronomical Society, vol. 498, no. 2. Oxford University Press, pp.
3043–3059, 2020.'
ista: 'Matthee JJ, Pezzulli G, Mackenzie R, Cantalupo S, Kusakabe H, Leclercq F,
Sobral D, Richard J, Wisotzki L, Lilly S, Boogaard L, Marino R, Maseda M, Nanayakkara
T. 2020. The nature of CR7 revealed with MUSE: A young starburst powering extended
Ly α emission at z = 6.6. Monthly Notices of the Royal Astronomical Society. 498(2),
3043–3059.'
mla: 'Matthee, Jorryt J., et al. “The Nature of CR7 Revealed with MUSE: A Young
Starburst Powering Extended Ly α Emission at z = 6.6.” Monthly Notices of the
Royal Astronomical Society, vol. 498, no. 2, Oxford University Press, 2020,
pp. 3043–59, doi:10.1093/mnras/staa2550.'
short: J.J. Matthee, G. Pezzulli, R. Mackenzie, S. Cantalupo, H. Kusakabe, F. Leclercq,
D. Sobral, J. Richard, L. Wisotzki, S. Lilly, L. Boogaard, R. Marino, M. Maseda,
T. Nanayakkara, Monthly Notices of the Royal Astronomical Society 498 (2020) 3043–3059.
date_created: 2022-07-07T10:36:01Z
date_published: 2020-10-01T00:00:00Z
date_updated: 2022-08-18T11:04:05Z
day: '01'
doi: 10.1093/mnras/staa2550
extern: '1'
external_id:
arxiv:
- '2008.01731'
intvolume: ' 498'
issue: '2'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- 'galaxies: evolution'
- 'galaxies: high-redshift'
- dark ages
- reionization
- first stars
- 'cosmology: observations'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/2008.01731
month: '10'
oa: 1
oa_version: Preprint
page: 3043-3059
publication: Monthly Notices of the Royal Astronomical Society
publication_identifier:
eissn:
- 1365-2966
issn:
- 0035-8711
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'The nature of CR7 revealed with MUSE: A young starburst powering extended
Ly α emission at z = 6.6'
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 498
year: '2020'
...
---
_id: '11534'
abstract:
- lang: eng
text: The observed properties of the Lyman-α (Ly α) emission line are a powerful
probe of neutral gas in and around galaxies. We present spatially resolved Ly α
spectroscopy with VLT/MUSE targeting VR7, a UV-luminous galaxy at z = 6.532 with
moderate Ly α equivalent width (EW0 ≈ 38 Å). These data are combined with deep
resolved [CII]158μm spectroscopy obtained with ALMA and UV imaging from HST and
we also detect UV continuum with MUSE. Ly α emission is clearly detected with
S/N ≈ 40 and FWHM of 374 km s−1. Ly α and [C II] are similarly extended beyond
the UV, with effective radius reff = 2.1 ± 0.2 kpc for a single exponential model
or reff,Lyα,halo=3.45+1.08−0.87 kpc when measured jointly with the UV continuum.
The Ly α profile is broader and redshifted with respect to the [C II] line (by
213 km s−1), but there are spatial variations that are qualitatively similar in
both lines and coincide with resolved UV components. This suggests that the emission
originates from two components with plausibly different H I column densities.
We place VR7 in the context of other galaxies at similar and lower redshift. The
Ly α halo scale length is similar at different redshifts and velocity shifts with
respect to the systemic are typically smaller. Overall, we find little indications
of a more neutral vicinity at higher redshift. This means that the local (∼10 kpc)
neutral gas conditions that determine the observed Ly α properties in VR7 resemble
the conditions in post-reionization galaxies.
acknowledgement: 'We thank the referee for their suggestions and constructive comments
that helped to improve the presentation of our results. Based on observations obtained
with the Very Large Telescope, program 99.A-0462. Based on observations made with
the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute,
which is operated by the Association of Universities for Research in Astronomy,
Inc., under NASA contract NAS 5-26555. These observations are associated with program
#14699. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2017.1.01451.S.
ALMA is a partnership of ESO (representing its member states), NSF (USA), and NINS
(Japan), together with NRC (Canada) and NSC and ASIAA (Taiwan) and KASI (Republic
of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory
is operated by ESO, AUI/NRAO, and NAOJ. MG acknowledges support from NASA grant
NNX17AK58G. GP and SC gratefully acknowledge support from Swiss National Science
Foundation grant PP00P2 163824. BD acknowledges financial support from the National
Science Foundation, grant number 1716907. We have benefited greatly from the public
available programming language PYTHON, including the NUMPY, MATPLOTLIB, SCIPY (Jones
et al. 2001; Hunter 2007; van der Walt, Colbert & Varoquaux 2011) and ASTROPY (Astropy
Collaboration 2013) packages, the astronomical imaging tools SEXTRACTOR, SWARP,
and SCAMP (Bertin & Arnouts 1996; Bertin 2006, 2010) and the TOPCAT analysis tool
(Taylor 2013).'
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Jorryt J
full_name: Matthee, Jorryt J
id: 7439a258-f3c0-11ec-9501-9df22fe06720
last_name: Matthee
orcid: 0000-0003-2871-127X
- first_name: David
full_name: Sobral, David
last_name: Sobral
- first_name: Max
full_name: Gronke, Max
last_name: Gronke
- first_name: Gabriele
full_name: Pezzulli, Gabriele
last_name: Pezzulli
- first_name: Sebastiano
full_name: Cantalupo, Sebastiano
last_name: Cantalupo
- first_name: Huub
full_name: Röttgering, Huub
last_name: Röttgering
- first_name: Behnam
full_name: Darvish, Behnam
last_name: Darvish
- first_name: Sérgio
full_name: Santos, Sérgio
last_name: Santos
citation:
ama: Matthee JJ, Sobral D, Gronke M, et al. Resolved Lyman-α properties of a luminous
Lyman-break galaxy in a large ionized bubble at z = 6.53 . Monthly Notices
of the Royal Astronomical Society. 2020;492(2):1778-1790. doi:10.1093/mnras/stz3554
apa: Matthee, J. J., Sobral, D., Gronke, M., Pezzulli, G., Cantalupo, S., Röttgering,
H., … Santos, S. (2020). Resolved Lyman-α properties of a luminous Lyman-break
galaxy in a large ionized bubble at z = 6.53 . Monthly Notices of the Royal
Astronomical Society. Oxford University Press. https://doi.org/10.1093/mnras/stz3554
chicago: Matthee, Jorryt J, David Sobral, Max Gronke, Gabriele Pezzulli, Sebastiano
Cantalupo, Huub Röttgering, Behnam Darvish, and Sérgio Santos. “Resolved Lyman-α
Properties of a Luminous Lyman-Break Galaxy in a Large Ionized Bubble at z = 6.53
.” Monthly Notices of the Royal Astronomical Society. Oxford University
Press, 2020. https://doi.org/10.1093/mnras/stz3554.
ieee: J. J. Matthee et al., “Resolved Lyman-α properties of a luminous Lyman-break
galaxy in a large ionized bubble at z = 6.53 ,” Monthly Notices of the Royal
Astronomical Society, vol. 492, no. 2. Oxford University Press, pp. 1778–1790,
2020.
ista: Matthee JJ, Sobral D, Gronke M, Pezzulli G, Cantalupo S, Röttgering H, Darvish
B, Santos S. 2020. Resolved Lyman-α properties of a luminous Lyman-break galaxy
in a large ionized bubble at z = 6.53 . Monthly Notices of the Royal Astronomical
Society. 492(2), 1778–1790.
mla: Matthee, Jorryt J., et al. “Resolved Lyman-α Properties of a Luminous Lyman-Break
Galaxy in a Large Ionized Bubble at z = 6.53 .” Monthly Notices of the Royal
Astronomical Society, vol. 492, no. 2, Oxford University Press, 2020, pp.
1778–90, doi:10.1093/mnras/stz3554.
short: J.J. Matthee, D. Sobral, M. Gronke, G. Pezzulli, S. Cantalupo, H. Röttgering,
B. Darvish, S. Santos, Monthly Notices of the Royal Astronomical Society 492 (2020)
1778–1790.
date_created: 2022-07-07T12:21:36Z
date_published: 2020-02-01T00:00:00Z
date_updated: 2022-08-18T11:29:53Z
day: '01'
doi: 10.1093/mnras/stz3554
extern: '1'
external_id:
arxiv:
- '1909.06376'
intvolume: ' 492'
issue: '2'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- 'galaxies: evolution'
- 'galaxies: high-redshift'
- dark ages
- reionization
- first stars
- 'cosmology: observations'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1909.06376
month: '02'
oa: 1
oa_version: Preprint
page: 1778-1790
publication: Monthly Notices of the Royal Astronomical Society
publication_identifier:
eissn:
- 1365-2966
issn:
- 0035-8711
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Resolved Lyman-α properties of a luminous Lyman-break galaxy in a large ionized
bubble at z = 6.53 '
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 492
year: '2020'
...
---
_id: '13466'
abstract:
- lang: eng
text: "Context. A majority of massive stars are part of binary systems, a large
fraction of which will inevitably interact during their lives. Binary-interaction
products (BiPs), that is, stars affected by such interaction, are expected to
be commonly present in stellar populations. BiPs are thus a crucial ingredient
in the understanding of stellar evolution.\r\nAims. We aim to identify and characterize
a statistically significant sample of BiPs by studying clusters of 10 − 40 Myr,
an age at which binary population models predict the abundance of BiPs to be highest.
One example of such a cluster is NGC 330 in the Small Magellanic Cloud.\r\nMethods.
Using MUSE WFM-AO observations of NGC 330, we resolved the dense cluster core
for the first time and were able to extract spectra of its entire massive star
population. We developed an automated spectral classification scheme based on
the equivalent widths of spectral lines in the red part of the spectrum.\r\nResults.
We characterize the massive star content of the core of NGC 330, which contains
more than 200 B stars, 2 O stars, 6 A-type supergiants, and 11 red supergiants.
We find a lower limit on the Be star fraction of 32 ± 3% in the whole sample.
It increases to at least 46 ± 10% when we only consider stars brighter than V = 17 mag.
We estimate an age of the cluster core between 35 and 40 Myr and a total cluster
mass of 88−18+17 × 103 M⊙.\r\nConclusions. We find that the population in the
cluster core is different than the population in the outskirts: while the stellar
content in the core appears to be older than the stars in the outskirts, the Be
star fraction and the observed binary fraction are significantly higher. Furthermore,
we detect several BiP candidates that will be subject of future studies."
article_number: A51
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: J.
full_name: Bodensteiner, J.
last_name: Bodensteiner
- first_name: H.
full_name: Sana, H.
last_name: Sana
- first_name: L.
full_name: Mahy, L.
last_name: Mahy
- first_name: L. R.
full_name: Patrick, L. R.
last_name: Patrick
- first_name: A.
full_name: de Koter, A.
last_name: de Koter
- first_name: S. E.
full_name: de Mink, S. E.
last_name: de Mink
- first_name: C. J.
full_name: Evans, C. J.
last_name: Evans
- first_name: Ylva Louise Linsdotter
full_name: Götberg, Ylva Louise Linsdotter
id: d0648d0c-0f64-11ee-a2e0-dd0faa2e4f7d
last_name: Götberg
orcid: 0000-0002-6960-6911
- first_name: N.
full_name: Langer, N.
last_name: Langer
- first_name: D. J.
full_name: Lennon, D. J.
last_name: Lennon
- first_name: F. R. N.
full_name: Schneider, F. R. N.
last_name: Schneider
- first_name: F.
full_name: Tramper, F.
last_name: Tramper
citation:
ama: Bodensteiner J, Sana H, Mahy L, et al. The young massive SMC cluster NGC 330
seen by MUSE. Astronomy & Astrophysics. 2020;634. doi:10.1051/0004-6361/201936743
apa: Bodensteiner, J., Sana, H., Mahy, L., Patrick, L. R., de Koter, A., de Mink,
S. E., … Tramper, F. (2020). The young massive SMC cluster NGC 330 seen by MUSE.
Astronomy & Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/201936743
chicago: Bodensteiner, J., H. Sana, L. Mahy, L. R. Patrick, A. de Koter, S. E. de
Mink, C. J. Evans, et al. “The Young Massive SMC Cluster NGC 330 Seen by MUSE.”
Astronomy & Astrophysics. EDP Sciences, 2020. https://doi.org/10.1051/0004-6361/201936743.
ieee: J. Bodensteiner et al., “The young massive SMC cluster NGC 330 seen
by MUSE,” Astronomy & Astrophysics, vol. 634. EDP Sciences, 2020.
ista: Bodensteiner J, Sana H, Mahy L, Patrick LR, de Koter A, de Mink SE, Evans
CJ, Götberg YLL, Langer N, Lennon DJ, Schneider FRN, Tramper F. 2020. The young
massive SMC cluster NGC 330 seen by MUSE. Astronomy & Astrophysics. 634, A51.
mla: Bodensteiner, J., et al. “The Young Massive SMC Cluster NGC 330 Seen by MUSE.”
Astronomy & Astrophysics, vol. 634, A51, EDP Sciences, 2020, doi:10.1051/0004-6361/201936743.
short: J. Bodensteiner, H. Sana, L. Mahy, L.R. Patrick, A. de Koter, S.E. de Mink,
C.J. Evans, Y.L.L. Götberg, N. Langer, D.J. Lennon, F.R.N. Schneider, F. Tramper,
Astronomy & Astrophysics 634 (2020).
date_created: 2023-08-03T10:13:29Z
date_published: 2020-02-05T00:00:00Z
date_updated: 2023-08-09T12:50:01Z
day: '05'
doi: 10.1051/0004-6361/201936743
extern: '1'
external_id:
arxiv:
- '1911.03477'
intvolume: ' 634'
keyword:
- 'stars: massive / stars: emission-line / Be / binaries: spectroscopic / blue stragglers
/ Magellanic Clouds'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.1051/0004-6361/201936743
month: '02'
oa: 1
oa_version: Published Version
publication: Astronomy & Astrophysics
publication_identifier:
eissn:
- 1432-0746
issn:
- 0004-6361
publication_status: published
publisher: EDP Sciences
quality_controlled: '1'
scopus_import: '1'
status: public
title: The young massive SMC cluster NGC 330 seen by MUSE
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 634
year: '2020'
...
---
_id: '11505'
abstract:
- lang: eng
text: "Contact. This paper presents the results obtained with the Multi-Unit Spectroscopic
Explorer (MUSE) at the ESO Very Large Telescope on the faint end of the Lyman-alpha
luminosity function (LF) based on deep observations of four lensing clusters.
The goal of our project is to set strong constraints on the relative contribution
of the Lyman-alpha emitter (LAE) population to cosmic reionization.\r\n\r\nAims.
The precise aim of the present study is to further constrain the abundance of
LAEs by taking advantage of the magnification provided by lensing clusters to
build a blindly selected sample of galaxies which is less biased than current
blank field samples in redshift and luminosity. By construction, this sample of
LAEs is complementary to those built from deep blank fields, whether observed
by MUSE or by other facilities, and makes it possible to determine the shape of
the LF at fainter levels, as well as its evolution with redshift.\r\n\r\nMethods.
We selected a sample of 156 LAEs with redshifts between 2.9 ≤ z ≤ 6.7 and magnification-corrected
luminosities in the range 39 ≲ log LLyα [erg s−1] ≲43. To properly take into account
the individual differences in detection conditions between the LAEs when computing
the LF, including lensing configurations, and spatial and spectral morphologies,
the non-parametric 1/Vmax method was adopted. The price to pay to benefit from
magnification is a reduction of the effective volume of the survey, together with
a more complex analysis procedure to properly determine the effective volume Vmax
for each galaxy. In this paper we present a complete procedure for the determination
of the LF based on IFU detections in lensing clusters. This procedure, including
some new methods for masking, effective volume integration and (individual) completeness
determinations, has been fully automated when possible, and it can be easily generalized
to the analysis of IFU observations in blank fields.\r\n\r\nResults. As a result
of this analysis, the Lyman-alpha LF has been obtained in four different redshift
bins: 2.9 < z < 6, 7, 2.9 < z < 4.0, 4.0 < z < 5.0, and 5.0 < z < 6.7
with constraints down to log LLyα = 40.5. From our data only, no significant evolution
of LF mean slope can be found. When performing a Schechter analysis also including
data from the literature to complete the present sample towards the brightest
luminosities, a steep faint end slope was measured varying from α = −1.69−0.08+0.08
to α = −1.87−0.12+0.12 between the lowest and the highest redshift bins.\r\n\r\nConclusions.
The contribution of the LAE population to the star formation rate density at z ∼ 6
is ≲50% depending on the luminosity limit considered, which is of the same order
as the Lyman-break galaxy (LBG) contribution. The evolution of the LAE contribution
with redshift depends on the assumed escape fraction of Lyman-alpha photons, and
appears to slightly increase with increasing redshift when this fraction is conservatively
set to one. Depending on the intersection between the LAE/LBG populations, the
contribution of the observed galaxies to the ionizing flux may suffice to keep
the universe ionized at z ∼ 6."
acknowledgement: We thank the anonymous referee for their critical review and useful
suggestions. This work has been carried out thanks to the support of the OCEVU Labex
(ANR-11-LABX-0060) and the A*MIDEX project (ANR-11-IDEX-0001-02) funded by the “Investissements
d’Avenir” French government programme managed by the ANR. Partially funded by the
ERC starting grant CALENDS (JR, VP, BC, JM), the Agence Nationale de la recherche
bearing the reference ANR-13-BS05-0010-02 (FOGHAR), and the “Programme National
de Cosmologie and Galaxies” (PNCG) of CNRS/INSU, France. GdV, RP, JR, GM, JM, BC,
and VP also acknowledge support by the Programa de Cooperacion Cientifica – ECOS
SUD Program C16U02. NL acknowledges funding from the European Research Council (ERC)
under the European Union’s Horizon 2020 research and innovation programme (grant
agreement No 669253), ABD acknowledges support from the ERC advanced grant “Cosmic
Gas”. LW acknowledges support by the Competitive Fund of the Leibniz Association
through grant SAW-2015-AIP-2, and TG acknowledges support from the European Research
Council under grant agreement ERC-stg-757258 (TRIPLE).. Based on observations made
with ESO Telescopes at the La Silla Paranal Observatory under programme IDs 060.A-9345,
094.A-0115, 095.A-0181, 096.A-0710, 097.A0269, 100.A-0249, and 294.A-5032. Also
based on observations obtained with the NASA/ESA Hubble Space Telescope, retrieved
from the Mikulski Archive for Space Telescopes (MAST) at the Space Telescope Science
Institute (STScI). STScI is operated by the Association of Universities for Research
in Astronomy, Inc. under NASA contract NAS 5-26555. This research made use of Astropy,
a community-developed core Python package for Astronomy (Astropy Collaboration 2013).
All plots in this paper were created using Matplotlib (Hunter 2007).
article_number: A3
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: G.
full_name: de La Vieuville, G.
last_name: de La Vieuville
- first_name: D.
full_name: Bina, D.
last_name: Bina
- first_name: R.
full_name: Pello, R.
last_name: Pello
- first_name: G.
full_name: Mahler, G.
last_name: Mahler
- first_name: J.
full_name: Richard, J.
last_name: Richard
- first_name: A. B.
full_name: Drake, A. B.
last_name: Drake
- first_name: E. C.
full_name: Herenz, E. C.
last_name: Herenz
- first_name: F. E.
full_name: Bauer, F. E.
last_name: Bauer
- first_name: B.
full_name: Clément, B.
last_name: Clément
- first_name: D.
full_name: Lagattuta, D.
last_name: Lagattuta
- first_name: N.
full_name: Laporte, N.
last_name: Laporte
- first_name: J.
full_name: Martinez, J.
last_name: Martinez
- first_name: V.
full_name: Patrício, V.
last_name: Patrício
- first_name: L.
full_name: Wisotzki, L.
last_name: Wisotzki
- first_name: J.
full_name: Zabl, J.
last_name: Zabl
- first_name: R. J.
full_name: Bouwens, R. J.
last_name: Bouwens
- first_name: T.
full_name: Contini, T.
last_name: Contini
- first_name: T.
full_name: Garel, T.
last_name: Garel
- first_name: B.
full_name: Guiderdoni, B.
last_name: Guiderdoni
- first_name: R. A.
full_name: Marino, R. A.
last_name: Marino
- first_name: M. V.
full_name: Maseda, M. V.
last_name: Maseda
- first_name: Jorryt J
full_name: Matthee, Jorryt J
id: 7439a258-f3c0-11ec-9501-9df22fe06720
last_name: Matthee
orcid: 0000-0003-2871-127X
- first_name: J.
full_name: Schaye, J.
last_name: Schaye
- first_name: G.
full_name: Soucail, G.
last_name: Soucail
citation:
ama: de La Vieuville G, Bina D, Pello R, et al. Faint end of the z ∼ 3–7 luminosity
function of Lyman-alpha emitters behind lensing clusters observed with MUSE. Astronomy
& Astrophysics. 2019;628. doi:10.1051/0004-6361/201834471
apa: de La Vieuville, G., Bina, D., Pello, R., Mahler, G., Richard, J., Drake, A.
B., … Soucail, G. (2019). Faint end of the z ∼ 3–7 luminosity function of Lyman-alpha
emitters behind lensing clusters observed with MUSE. Astronomy & Astrophysics.
EDP Sciences. https://doi.org/10.1051/0004-6361/201834471
chicago: La Vieuville, G. de, D. Bina, R. Pello, G. Mahler, J. Richard, A. B. Drake,
E. C. Herenz, et al. “Faint End of the z ∼ 3–7 Luminosity Function of Lyman-Alpha
Emitters behind Lensing Clusters Observed with MUSE.” Astronomy & Astrophysics.
EDP Sciences, 2019. https://doi.org/10.1051/0004-6361/201834471.
ieee: G. de La Vieuville et al., “Faint end of the z ∼ 3–7 luminosity function
of Lyman-alpha emitters behind lensing clusters observed with MUSE,” Astronomy
& Astrophysics, vol. 628. EDP Sciences, 2019.
ista: de La Vieuville G, Bina D, Pello R, Mahler G, Richard J, Drake AB, Herenz
EC, Bauer FE, Clément B, Lagattuta D, Laporte N, Martinez J, Patrício V, Wisotzki
L, Zabl J, Bouwens RJ, Contini T, Garel T, Guiderdoni B, Marino RA, Maseda MV,
Matthee JJ, Schaye J, Soucail G. 2019. Faint end of the z ∼ 3–7 luminosity function
of Lyman-alpha emitters behind lensing clusters observed with MUSE. Astronomy
& Astrophysics. 628, A3.
mla: de La Vieuville, G., et al. “Faint End of the z ∼ 3–7 Luminosity Function of
Lyman-Alpha Emitters behind Lensing Clusters Observed with MUSE.” Astronomy
& Astrophysics, vol. 628, A3, EDP Sciences, 2019, doi:10.1051/0004-6361/201834471.
short: G. de La Vieuville, D. Bina, R. Pello, G. Mahler, J. Richard, A.B. Drake,
E.C. Herenz, F.E. Bauer, B. Clément, D. Lagattuta, N. Laporte, J. Martinez, V.
Patrício, L. Wisotzki, J. Zabl, R.J. Bouwens, T. Contini, T. Garel, B. Guiderdoni,
R.A. Marino, M.V. Maseda, J.J. Matthee, J. Schaye, G. Soucail, Astronomy &
Astrophysics 628 (2019).
date_created: 2022-07-06T10:09:36Z
date_published: 2019-07-25T00:00:00Z
date_updated: 2022-07-19T09:36:31Z
day: '25'
doi: 10.1051/0004-6361/201834471
extern: '1'
external_id:
arxiv:
- '1905.13696'
intvolume: ' 628'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- 'gravitational lensing: strong / galaxies: high-redshift / dark ages'
- reionization
- 'first stars / galaxies: clusters: general / galaxies: luminosity function'
- mass function
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1905.13696
month: '07'
oa: 1
oa_version: Published Version
publication: Astronomy & Astrophysics
publication_identifier:
eissn:
- 1432-0746
issn:
- 0004-6361
publication_status: published
publisher: EDP Sciences
quality_controlled: '1'
scopus_import: '1'
status: public
title: Faint end of the z ∼ 3–7 luminosity function of Lyman-alpha emitters behind
lensing clusters observed with MUSE
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 628
year: '2019'
...
---
_id: '11541'
abstract:
- lang: eng
text: We present new Hubble Space Telescope (HST)/WFC3 observations and re-analyse
VLT data to unveil the continuum, variability, and rest-frame ultraviolet (UV)
lines of the multiple UV clumps of the most luminous Lyα emitter at z = 6.6, CR7
(COSMOS Redshift 7). Our re-reduced, flux-calibrated X-SHOOTER spectra of CR7
reveal an He II emission line in observations obtained along the major axis of
Lyα emission with the best seeing conditions. He II is spatially offset by ≈+0.8
arcsec from the peak of Lyα emission, and it is found towards clump B. Our WFC3
grism spectra detects the UV continuum of CR7’s clump A, yielding a power law
with β=−2.5+0.6−0.7 and MUV=−21.87+0.25−0.20. No significant variability is found
for any of the UV clumps on their own, but there is tentative (≈2.2 σ) brightening
of CR7 in F110W as a whole from 2012 to 2017. HST grism data fail to robustly
detect rest-frame UV lines in any of the clumps, implying fluxes ≲2×10−17 erg s−1 cm−2
(3σ). We perform CLOUDY modelling to constrain the metallicity and the ionizing
nature of CR7. CR7 seems to be actively forming stars without any clear active
galactic nucleus activity in clump A, consistent with a metallicity of ∼0.05–0.2 Z⊙.
Component C or an interclump component between B and C may host a high ionization
source. Our results highlight the need for spatially resolved information to study
the formation and assembly of early galaxies.
acknowledgement: We thank the anonymous reviewer for the numerous detailed comments
that led us to greatly improve the quality, extent, and statistical robustness of
this work. DS acknowledges financial support from the Netherlands Organisation for
Scientific research through a Veni fellowship. JM acknowledges the support of a
Huygens PhD fellowship from Leiden University. AF acknowledges support from the
ERC Advanced Grant INTERSTELLAR H2020/740120. BD acknowledges financial support
from NASA through the Astrophysics Data Analysis Program, grant number NNX12AE20G
and the National Science Foundation, grant number 1716907. We are thankful for several
discussions and constructive comments from Johannes Zabl, Eros Vanzella, Bo Milvang-Jensen,
Henry McCracken, Max Gronke, Mark Dijkstra, Richard Ellis, and Nicolas Laporte.
We also thank Umar Burhanudin and Izzy Garland for taking part in the XGAL internship
in Lancaster and for exploring the HST grism data independently. Based on observations
obtained with HST/WFC3 programs 12578, 14495, and 14596. Based on observations of
the National Japanese Observatory with the Suprime-Cam on the Subaru telescope (S14A-086)
on the big island of Hawaii. This work is based in part on data products produced
at TERAPIX available at the Canadian Astronomy Data Centre as part of the Canada–France–Hawaii
Telescope Legacy Survey, a collaborative project of NRC and CNRS. Based on data
products from observations made with ESO Telescopes at the La Silla Paranal Observatory
under ESO programme IDs 294.A-5018, 294.A-5039, 092.A 0786, 093.A-0561, 097.A0043,
097.A-0943, 098.A-0819, 298.A-5012, and 179.A-2005, and on data products produced
by TERAPIX and the Cambridge Astronomy Survey Unit on behalf of the UltraVISTA consortium.
The authors acknowledge the award of service time (SW2014b20) on the William Herschel
Telescope (WHT). WHT and its service programme are operated on the island of La
Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos
of the Instituto de Astrofisica de Canarias. This research was supported by the
Munich Institute for Astro- and Particle Physics of the DFG cluster of excellence
‘Origin and Structure of the Universe’. We have benefitted immensely from the public
available programming language PYTHON, including NUMPY and SCIPY (Jones et al. 2001;
Van Der Walt, Colbert & Varoquaux 2011), MATPLOTLIB (Hunter 2007), ASTROPY (Astropy
Collaboration et al. 2013), and the TOPCAT analysis program (Taylor 2013). This
research has made use of the VizieR catalogue access tool, CDS, Strasbourg, France.
All data used for this paper are publicly available, and we make all reduced data
available with the refereed paper.
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: David
full_name: Sobral, David
last_name: Sobral
- first_name: Jorryt J
full_name: Matthee, Jorryt J
id: 7439a258-f3c0-11ec-9501-9df22fe06720
last_name: Matthee
orcid: 0000-0003-2871-127X
- first_name: Gabriel
full_name: Brammer, Gabriel
last_name: Brammer
- first_name: Andrea
full_name: Ferrara, Andrea
last_name: Ferrara
- first_name: Lara
full_name: Alegre, Lara
last_name: Alegre
- first_name: Huub
full_name: Röttgering, Huub
last_name: Röttgering
- first_name: Daniel
full_name: Schaerer, Daniel
last_name: Schaerer
- first_name: Bahram
full_name: Mobasher, Bahram
last_name: Mobasher
- first_name: Behnam
full_name: Darvish, Behnam
last_name: Darvish
citation:
ama: Sobral D, Matthee JJ, Brammer G, et al. On the nature and physical conditions
of the luminous Ly α emitter CR7 and its rest-frame UV components. Monthly
Notices of the Royal Astronomical Society. 2019;482(2):2422-2441. doi:10.1093/mnras/sty2779
apa: Sobral, D., Matthee, J. J., Brammer, G., Ferrara, A., Alegre, L., Röttgering,
H., … Darvish, B. (2019). On the nature and physical conditions of the luminous
Ly α emitter CR7 and its rest-frame UV components. Monthly Notices of the Royal
Astronomical Society. Oxford University Press. https://doi.org/10.1093/mnras/sty2779
chicago: Sobral, David, Jorryt J Matthee, Gabriel Brammer, Andrea Ferrara, Lara
Alegre, Huub Röttgering, Daniel Schaerer, Bahram Mobasher, and Behnam Darvish.
“On the Nature and Physical Conditions of the Luminous Ly α Emitter CR7 and Its
Rest-Frame UV Components.” Monthly Notices of the Royal Astronomical Society.
Oxford University Press, 2019. https://doi.org/10.1093/mnras/sty2779.
ieee: D. Sobral et al., “On the nature and physical conditions of the luminous
Ly α emitter CR7 and its rest-frame UV components,” Monthly Notices of the
Royal Astronomical Society, vol. 482, no. 2. Oxford University Press, pp.
2422–2441, 2019.
ista: Sobral D, Matthee JJ, Brammer G, Ferrara A, Alegre L, Röttgering H, Schaerer
D, Mobasher B, Darvish B. 2019. On the nature and physical conditions of the luminous
Ly α emitter CR7 and its rest-frame UV components. Monthly Notices of the Royal
Astronomical Society. 482(2), 2422–2441.
mla: Sobral, David, et al. “On the Nature and Physical Conditions of the Luminous
Ly α Emitter CR7 and Its Rest-Frame UV Components.” Monthly Notices of the
Royal Astronomical Society, vol. 482, no. 2, Oxford University Press, 2019,
pp. 2422–41, doi:10.1093/mnras/sty2779.
short: D. Sobral, J.J. Matthee, G. Brammer, A. Ferrara, L. Alegre, H. Röttgering,
D. Schaerer, B. Mobasher, B. Darvish, Monthly Notices of the Royal Astronomical
Society 482 (2019) 2422–2441.
date_created: 2022-07-08T10:40:05Z
date_published: 2019-01-01T00:00:00Z
date_updated: 2022-08-19T06:49:36Z
day: '01'
doi: 10.1093/mnras/sty2779
extern: '1'
external_id:
arxiv:
- '1710.08422'
intvolume: ' 482'
issue: '2'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- 'galaxies: evolution'
- 'galaxies: high-redshift'
- 'galaxies: ISM'
- 'cosmology: observations'
- dark ages
- reionization
- first stars
- early Universe
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1710.08422
month: '01'
oa: 1
oa_version: Preprint
page: 2422-2441
publication: Monthly Notices of the Royal Astronomical Society
publication_identifier:
eissn:
- 1365-2966
issn:
- 0035-8711
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: On the nature and physical conditions of the luminous Ly α emitter CR7 and
its rest-frame UV components
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 482
year: '2019'
...
---
_id: '11615'
abstract:
- lang: eng
text: The recently published Kepler mission Data Release 25 (DR25) reported on ∼197 000
targets observed during the mission. Despite this, no wide search for red giants
showing solar-like oscillations have been made across all stars observed in Kepler’s
long-cadence mode. In this work, we perform this task using custom apertures on
the Kepler pixel files and detect oscillations in 21 914 stars, representing the
largest sample of solar-like oscillating stars to date. We measure their frequency
at maximum power, νmax, down to νmax≃4μHz and obtain log (g) estimates with a
typical uncertainty below 0.05 dex, which is superior to typical measurements
from spectroscopy. Additionally, the νmax distribution of our detections show
good agreement with results from a simulated model of the Milky Way, with a ratio
of observed to predicted stars of 0.992 for stars with 10<νmax<270μHz. Among our
red giant detections, we find 909 to be dwarf/subgiant stars whose flux signal
is polluted by a neighbouring giant as a result of using larger photometric apertures
than those used by the NASA Kepler science processing pipeline. We further find
that only 293 of the polluting giants are known Kepler targets. The remainder
comprises over 600 newly identified oscillating red giants, with many expected
to belong to the Galactic halo, serendipitously falling within the Kepler pixel
files of targeted stars.
acknowledgement: Funding for this Discovery mission is provided by NASA’s Science
mission Directorate. We thank the entire Kepler team without whom this investigation
would not be possible. DS is the recipient of an Australian Research Council Future
Fellowship (project number FT1400147). RAG acknowledges the support from CNES. SM
acknowledges support from NASA grant NNX15AF13G, NSF grant AST-1411685, and the
Ramon y Cajal fellowship number RYC-2015-17697. ILC acknowledges scholarship support
from the University of Sydney. We would like to thank Nicholas Barbara and Timothy
Bedding for providing us with a list of variable stars that helped to validate a
number of detections in this study. We also thank the group at the University of
Sydney for fruitful discussions. Finally, we gratefully acknowledge the support
of NVIDIA Corporation with the donation of the Titan Xp GPU used for this research.
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Marc
full_name: Hon, Marc
last_name: Hon
- first_name: Dennis
full_name: Stello, Dennis
last_name: Stello
- first_name: Rafael A
full_name: García, Rafael A
last_name: García
- first_name: Savita
full_name: Mathur, Savita
last_name: Mathur
- first_name: Sanjib
full_name: Sharma, Sanjib
last_name: Sharma
- first_name: Isabel L
full_name: Colman, Isabel L
last_name: Colman
- first_name: Lisa Annabelle
full_name: Bugnet, Lisa Annabelle
id: d9edb345-f866-11ec-9b37-d119b5234501
last_name: Bugnet
orcid: 0000-0003-0142-4000
citation:
ama: Hon M, Stello D, García RA, et al. A search for red giant solar-like oscillations
in all Kepler data. Monthly Notices of the Royal Astronomical Society.
2019;485(4):5616-5630. doi:10.1093/mnras/stz622
apa: Hon, M., Stello, D., García, R. A., Mathur, S., Sharma, S., Colman, I. L.,
& Bugnet, L. A. (2019). A search for red giant solar-like oscillations in
all Kepler data. Monthly Notices of the Royal Astronomical Society. Oxford
University Press. https://doi.org/10.1093/mnras/stz622
chicago: Hon, Marc, Dennis Stello, Rafael A García, Savita Mathur, Sanjib Sharma,
Isabel L Colman, and Lisa Annabelle Bugnet. “A Search for Red Giant Solar-like
Oscillations in All Kepler Data.” Monthly Notices of the Royal Astronomical
Society. Oxford University Press, 2019. https://doi.org/10.1093/mnras/stz622.
ieee: M. Hon et al., “A search for red giant solar-like oscillations in all
Kepler data,” Monthly Notices of the Royal Astronomical Society, vol. 485,
no. 4. Oxford University Press, pp. 5616–5630, 2019.
ista: Hon M, Stello D, García RA, Mathur S, Sharma S, Colman IL, Bugnet LA. 2019.
A search for red giant solar-like oscillations in all Kepler data. Monthly Notices
of the Royal Astronomical Society. 485(4), 5616–5630.
mla: Hon, Marc, et al. “A Search for Red Giant Solar-like Oscillations in All Kepler
Data.” Monthly Notices of the Royal Astronomical Society, vol. 485, no.
4, Oxford University Press, 2019, pp. 5616–30, doi:10.1093/mnras/stz622.
short: M. Hon, D. Stello, R.A. García, S. Mathur, S. Sharma, I.L. Colman, L.A. Bugnet,
Monthly Notices of the Royal Astronomical Society 485 (2019) 5616–5630.
date_created: 2022-07-18T14:26:03Z
date_published: 2019-06-01T00:00:00Z
date_updated: 2022-08-22T07:35:19Z
day: '01'
doi: 10.1093/mnras/stz622
extern: '1'
external_id:
arxiv:
- '1903.00115'
intvolume: ' 485'
issue: '4'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- asteroseismology
- 'methods: data analysis'
- 'techniques: image processing'
- 'stars: oscillations'
- 'stars: statistics'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1903.00115
month: '06'
oa: 1
oa_version: Preprint
page: 5616-5630
publication: Monthly Notices of the Royal Astronomical Society
publication_identifier:
eissn:
- 1365-2966
issn:
- 0035-8711
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: A search for red giant solar-like oscillations in all Kepler data
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 485
year: '2019'
...
---
_id: '11623'
abstract:
- lang: eng
text: Brightness variations due to dark spots on the stellar surface encode information
about stellar surface rotation and magnetic activity. In this work, we analyze
the Kepler long-cadence data of 26,521 main-sequence stars of spectral types M
and K in order to measure their surface rotation and photometric activity level.
Rotation-period estimates are obtained by the combination of a wavelet analysis
and autocorrelation function of the light curves. Reliable rotation estimates
are determined by comparing the results from the different rotation diagnostics
and four data sets. We also measure the photometric activity proxy Sph using the
amplitude of the flux variations on an appropriate timescale. We report rotation
periods and photometric activity proxies for about 60% of the sample, including
4431 targets for which McQuillan et al. did not report a rotation period. For
the common targets with rotation estimates in this study and in McQuillan et al.,
our rotation periods agree within 99%. In this work, we also identify potential
polluters, such as misclassified red giants and classical pulsator candidates.
Within the parameter range we study, there is a mild tendency for hotter stars
to have shorter rotation periods. The photometric activity proxy spans a wider
range of values with increasing effective temperature. The rotation period and
photometric activity proxy are also related, with Sph being larger for fast rotators.
Similar to McQuillan et al., we find a bimodal distribution of rotation periods.
acknowledgement: "The authors thank Róbert Szabó Paul G. Beck, Katrien Kolenberg,
and Isabel L. Colman for helping on the classification of stars. This paper includes
data collected by the Kepler mission and obtained from the MAST data archive at
the Space Telescope Science Institute (STScI). Funding for the Kepler mission is
provided by the National Aeronautics and Space Administration (NASA) Science Mission
Directorate. STScI is operated by the Association of Universities for Research in
Astronomy, Inc., under NASA contract NAS 5–26555. A.R.G.S. acknowledges the support
from NASA under grant NNX17AF27G. R.A.G. and L.B. acknowledge the support from PLATO
and GOLF CNES grants. S.M. acknowledges the support from the Ramon y Cajal fellowship
number RYC-2015-17697. T.S.M. acknowledges support from a Visiting Fellowship at
the Max Planck Institute for Solar System Research. This research has made use of
the NASA Exoplanet Archive, which is operated by the California Institute of Technology,
under contract with the National Aeronautics and Space Administration under the
Exoplanet Exploration Program.\r\n\r\nSoftware: KADACS (García et al. 2011), NumPy
(van der Walt et al. 2011), SciPy (Jones et al. 2001), Matplotlib (Hunter 2007).\r\n\r\nFacilities:
MAST - , Kepler Eclipsing Binary Catalog - , Exoplanet Archive. -"
article_number: '21'
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: A. R. G.
full_name: Santos, A. R. G.
last_name: Santos
- first_name: R. A.
full_name: García, R. A.
last_name: García
- first_name: S.
full_name: Mathur, S.
last_name: Mathur
- first_name: Lisa Annabelle
full_name: Bugnet, Lisa Annabelle
id: d9edb345-f866-11ec-9b37-d119b5234501
last_name: Bugnet
orcid: 0000-0003-0142-4000
- first_name: J. L.
full_name: van Saders, J. L.
last_name: van Saders
- first_name: T. S.
full_name: Metcalfe, T. S.
last_name: Metcalfe
- first_name: G. V. A.
full_name: Simonian, G. V. A.
last_name: Simonian
- first_name: M. H.
full_name: Pinsonneault, M. H.
last_name: Pinsonneault
citation:
ama: Santos ARG, García RA, Mathur S, et al. Surface rotation and photometric activity
for Kepler targets. I. M and K main-sequence stars. The Astrophysical Journal
Supplement Series. 2019;244(1). doi:10.3847/1538-4365/ab3b56
apa: Santos, A. R. G., García, R. A., Mathur, S., Bugnet, L. A., van Saders, J.
L., Metcalfe, T. S., … Pinsonneault, M. H. (2019). Surface rotation and photometric
activity for Kepler targets. I. M and K main-sequence stars. The Astrophysical
Journal Supplement Series. IOP Publishing. https://doi.org/10.3847/1538-4365/ab3b56
chicago: Santos, A. R. G., R. A. García, S. Mathur, Lisa Annabelle Bugnet, J. L.
van Saders, T. S. Metcalfe, G. V. A. Simonian, and M. H. Pinsonneault. “Surface
Rotation and Photometric Activity for Kepler Targets. I. M and K Main-Sequence
Stars.” The Astrophysical Journal Supplement Series. IOP Publishing, 2019.
https://doi.org/10.3847/1538-4365/ab3b56.
ieee: A. R. G. Santos et al., “Surface rotation and photometric activity
for Kepler targets. I. M and K main-sequence stars,” The Astrophysical Journal
Supplement Series, vol. 244, no. 1. IOP Publishing, 2019.
ista: Santos ARG, García RA, Mathur S, Bugnet LA, van Saders JL, Metcalfe TS, Simonian
GVA, Pinsonneault MH. 2019. Surface rotation and photometric activity for Kepler
targets. I. M and K main-sequence stars. The Astrophysical Journal Supplement
Series. 244(1), 21.
mla: Santos, A. R. G., et al. “Surface Rotation and Photometric Activity for Kepler
Targets. I. M and K Main-Sequence Stars.” The Astrophysical Journal Supplement
Series, vol. 244, no. 1, 21, IOP Publishing, 2019, doi:10.3847/1538-4365/ab3b56.
short: A.R.G. Santos, R.A. García, S. Mathur, L.A. Bugnet, J.L. van Saders, T.S.
Metcalfe, G.V.A. Simonian, M.H. Pinsonneault, The Astrophysical Journal Supplement
Series 244 (2019).
date_created: 2022-07-19T09:21:58Z
date_published: 2019-09-19T00:00:00Z
date_updated: 2022-08-22T08:10:38Z
day: '19'
doi: 10.3847/1538-4365/ab3b56
extern: '1'
external_id:
arxiv:
- '1908.05222'
intvolume: ' 244'
issue: '1'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- 'methods: data analysis'
- 'stars: activity'
- 'stars: low-mass'
- 'stars: rotation'
- starspots
- 'techniques: photometric'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1908.05222
month: '09'
oa: 1
oa_version: Preprint
publication: The Astrophysical Journal Supplement Series
publication_identifier:
issn:
- 0067-0049
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: Surface rotation and photometric activity for Kepler targets. I. M and K main-sequence
stars
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 244
year: '2019'
...
---
_id: '11627'
abstract:
- lang: eng
text: 'For a solar-like star, the surface rotation evolves with time, allowing in
principle to estimate the age of a star from its surface rotation period. Here
we are interested in measuring surface rotation periods of solar-like stars observed
by the NASA mission Kepler. Different methods have been developed to track rotation
signals in Kepler photometric light curves: time-frequency analysis based on wavelet
techniques, autocorrelation and composite spectrum. We use the learning abilities
of random forest classifiers to take decisions during two crucial steps of the
analysis. First, given some input parameters, we discriminate the considered Kepler
targets between rotating MS stars, non-rotating MS stars, red giants, binaries
and pulsators. We then use a second classifier only on the MS rotating targets
to decide the best data analysis treatment.'
article_number: '1906.09609'
article_processing_charge: No
arxiv: 1
author:
- first_name: S. N.
full_name: Breton, S. N.
last_name: Breton
- first_name: Lisa Annabelle
full_name: Bugnet, Lisa Annabelle
id: d9edb345-f866-11ec-9b37-d119b5234501
last_name: Bugnet
orcid: 0000-0003-0142-4000
- first_name: A. R. G.
full_name: Santos, A. R. G.
last_name: Santos
- first_name: A. Le
full_name: Saux, A. Le
last_name: Saux
- first_name: S.
full_name: Mathur, S.
last_name: Mathur
- first_name: P. L.
full_name: Palle, P. L.
last_name: Palle
- first_name: R. A.
full_name: Garcia, R. A.
last_name: Garcia
citation:
ama: Breton SN, Bugnet LA, Santos ARG, et al. Determining surface rotation periods
of solar-like stars observed by the Kepler mission using machine learning techniques.
arXiv. doi:10.48550/arXiv.1906.09609
apa: Breton, S. N., Bugnet, L. A., Santos, A. R. G., Saux, A. L., Mathur, S., Palle,
P. L., & Garcia, R. A. (n.d.). Determining surface rotation periods of solar-like
stars observed by the Kepler mission using machine learning techniques. arXiv.
https://doi.org/10.48550/arXiv.1906.09609
chicago: Breton, S. N., Lisa Annabelle Bugnet, A. R. G. Santos, A. Le Saux, S. Mathur,
P. L. Palle, and R. A. Garcia. “Determining Surface Rotation Periods of Solar-like
Stars Observed by the Kepler Mission Using Machine Learning Techniques.” ArXiv,
n.d. https://doi.org/10.48550/arXiv.1906.09609.
ieee: S. N. Breton et al., “Determining surface rotation periods of solar-like
stars observed by the Kepler mission using machine learning techniques,” arXiv.
.
ista: Breton SN, Bugnet LA, Santos ARG, Saux AL, Mathur S, Palle PL, Garcia RA.
Determining surface rotation periods of solar-like stars observed by the Kepler
mission using machine learning techniques. arXiv, 1906.09609.
mla: Breton, S. N., et al. “Determining Surface Rotation Periods of Solar-like Stars
Observed by the Kepler Mission Using Machine Learning Techniques.” ArXiv,
1906.09609, doi:10.48550/arXiv.1906.09609.
short: S.N. Breton, L.A. Bugnet, A.R.G. Santos, A.L. Saux, S. Mathur, P.L. Palle,
R.A. Garcia, ArXiv (n.d.).
date_created: 2022-07-20T11:18:53Z
date_published: 2019-06-23T00:00:00Z
date_updated: 2022-08-22T08:16:53Z
day: '23'
doi: 10.48550/arXiv.1906.09609
extern: '1'
external_id:
arxiv:
- '1906.09609'
keyword:
- asteroseismology
- rotation
- solar-like stars
- kepler
- machine learning
- random forest
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1906.09609
month: '06'
oa: 1
oa_version: Preprint
publication: arXiv
publication_status: submitted
status: public
title: Determining surface rotation periods of solar-like stars observed by the Kepler
mission using machine learning techniques
type: preprint
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2019'
...
---
_id: '11630'
abstract:
- lang: eng
text: 'The second mission of NASA’s Kepler satellite, K2, has collected hundreds
of thousands of lightcurves for stars close to the ecliptic plane. This new sample
could increase the number of known pulsating stars and then improve our understanding
of those stars. For the moment only a few stars have been properly classified
and published. In this work, we present a method to automaticly classify K2 pulsating
stars using a Machine Learning technique called Random Forest. The objective is
to sort out the stars in four classes: red giant (RG), main-sequence Solar-like
stars (SL), classical pulsators (PULS) and Other. To do this we use the effective
temperatures and the luminosities of the stars as well as the FliPer features,
that measures the amount of power contained in the power spectral density. The
classifier now retrieves the right classification for more than 80% of the stars.'
article_number: '1906.09611'
article_processing_charge: No
arxiv: 1
author:
- first_name: A. Le
full_name: Saux, A. Le
last_name: Saux
- first_name: Lisa Annabelle
full_name: Bugnet, Lisa Annabelle
id: d9edb345-f866-11ec-9b37-d119b5234501
last_name: Bugnet
orcid: 0000-0003-0142-4000
- first_name: S.
full_name: Mathur, S.
last_name: Mathur
- first_name: S. N.
full_name: Breton, S. N.
last_name: Breton
- first_name: R. A.
full_name: Garcia, R. A.
last_name: Garcia
citation:
ama: Saux AL, Bugnet LA, Mathur S, Breton SN, Garcia RA. Automatic classification
of K2 pulsating stars using machine learning techniques. arXiv. doi:10.48550/arXiv.1906.09611
apa: Saux, A. L., Bugnet, L. A., Mathur, S., Breton, S. N., & Garcia, R. A.
(n.d.). Automatic classification of K2 pulsating stars using machine learning
techniques. arXiv. https://doi.org/10.48550/arXiv.1906.09611
chicago: Saux, A. Le, Lisa Annabelle Bugnet, S. Mathur, S. N. Breton, and R. A.
Garcia. “Automatic Classification of K2 Pulsating Stars Using Machine Learning
Techniques.” ArXiv, n.d. https://doi.org/10.48550/arXiv.1906.09611.
ieee: A. L. Saux, L. A. Bugnet, S. Mathur, S. N. Breton, and R. A. Garcia, “Automatic
classification of K2 pulsating stars using machine learning techniques,” arXiv.
.
ista: Saux AL, Bugnet LA, Mathur S, Breton SN, Garcia RA. Automatic classification
of K2 pulsating stars using machine learning techniques. arXiv, 1906.09611.
mla: Saux, A. Le, et al. “Automatic Classification of K2 Pulsating Stars Using Machine
Learning Techniques.” ArXiv, 1906.09611, doi:10.48550/arXiv.1906.09611.
short: A.L. Saux, L.A. Bugnet, S. Mathur, S.N. Breton, R.A. Garcia, ArXiv (n.d.).
date_created: 2022-07-21T06:57:10Z
date_published: 2019-06-23T00:00:00Z
date_updated: 2022-08-22T08:20:29Z
day: '23'
doi: 10.48550/arXiv.1906.09611
extern: '1'
external_id:
arxiv:
- '1906.09611'
keyword:
- asteroseismology - methods
- data analysis - thecniques
- machine learning - stars
- oscillations
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.48550/arXiv.1906.09611
month: '06'
oa: 1
oa_version: Preprint
publication: arXiv
publication_status: submitted
status: public
title: Automatic classification of K2 pulsating stars using machine learning techniques
type: preprint
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2019'
...
---
_id: '11508'
abstract:
- lang: eng
text: Distant luminous Lyman-α emitters (LAEs) are excellent targets for spectroscopic
observations of galaxies in the epoch of reionisation (EoR). We present deep high-resolution
(R = 5000) VLT/X-shooter observations, along with an extensive collection of photometric
data of COLA1, a proposed double peaked LAE at z = 6.6. We rule out the possibility
that COLA1’s emission line is an [OII] doublet at z = 1.475 on the basis of i)
the asymmetric red line-profile and flux ratio of the peaks (blue/red=0.31 ± 0.03)
and ii) an unphysical [OII]/Hα ratio ([OII]/Hα > 22). We show that COLA1’s observed
B-band flux is explained by a faint extended foreground LAE, for which we detect
Lyα and [OIII] at z = 2.142. We thus conclude that COLA1 is a real double-peaked
LAE at z = 6.593, the first discovered at z > 6. COLA1 is UV luminous (M1500 = −21.6 ± 0.3),
has a high equivalent width (EW0,Lyα = 120−40+50 Å) and very compact Lyα emission
(r50,Lyα = 0.33−0.04+0.07 kpc). Relatively weak inferred Hβ+[OIII] line-emission
from Spitzer/IRAC indicates an extremely low metallicity of Z < 1/20 Z⊙ or reduced
strength of nebular lines due to high escape of ionising photons. The small Lyα
peak separation of 220 ± 20 km s−1 implies a low HI column density and an ionising
photon escape fraction of ≈15 − 30%, providing the first direct evidence that
such galaxies contribute actively to the reionisation of the Universe at z > 6.
Based on simple estimates, we find that COLA1 could have provided just enough
photons to reionise its own ≈0.3 pMpc (2.3 cMpc) bubble, allowing the blue Lyα
line to be observed. However, we also discuss alternative scenarios explaining
the detected double peaked nature of COLA1. Our results show that future high-resolution
observations of statistical samples of double peaked LAEs at z > 5 are a promising
probe of the occurrence of ionised regions around galaxies in the EoR.
acknowledgement: JM acknowledges the award of a Huygens PhD fellowship from Leiden
University. MG acknowledges support from NASA grant NNX17AK58G. APA, PhD::SPACE
fellow, acknowledges support from the FCT through the fellowship PD/BD/52706/2014.
Based on observations made with ESO Telescopes at the La Silla Paranal Observatory
under programme IDs 294.A-5018, 098.A-0819, 099.A-0254 and 0100.A-0213. We are grateful
for the excellent data-sets from the COSMOS and UltraVISTA survey teams. This research
was supported by the Munich Institute for Astro- and Particle Physics (MIAPP) of
the DFG cluster of excellence “Origin and Structure of the Universe”. We thank the
referee for their comments that improved the paper. We also thank Christoph Behrens,
Len Cowie, Koki Kakiichi, Peter Laursen, Charlotte Mason, Eros Vanzella, Lewis Weinberger
and Johannes Zabl for discussions. We have benefited from the public available programming
language Python, including the numpy, matplotlib, scipy and astropy packages (Hunter
2007; Astropy Collaboration 2013), the astronomical imaging tools Swarp (Bertin
2010) and ds9 and the Topcat analysis tool (Taylor 2013).
article_number: A136
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Jorryt J
full_name: Matthee, Jorryt J
id: 7439a258-f3c0-11ec-9501-9df22fe06720
last_name: Matthee
orcid: 0000-0003-2871-127X
- first_name: David
full_name: Sobral, David
last_name: Sobral
- first_name: Max
full_name: Gronke, Max
last_name: Gronke
- first_name: Ana
full_name: Paulino-Afonso, Ana
last_name: Paulino-Afonso
- first_name: Mauro
full_name: Stefanon, Mauro
last_name: Stefanon
- first_name: Huub
full_name: Röttgering, Huub
last_name: Röttgering
citation:
ama: 'Matthee JJ, Sobral D, Gronke M, Paulino-Afonso A, Stefanon M, Röttgering H.
Confirmation of double peaked Lyα emission at z = 6.593: Witnessing a galaxy directly
contributing to the reionisation of the universe. Astronomy & Astrophysics.
2018;619. doi:10.1051/0004-6361/201833528'
apa: 'Matthee, J. J., Sobral, D., Gronke, M., Paulino-Afonso, A., Stefanon, M.,
& Röttgering, H. (2018). Confirmation of double peaked Lyα emission at z =
6.593: Witnessing a galaxy directly contributing to the reionisation of the universe.
Astronomy & Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/201833528'
chicago: 'Matthee, Jorryt J, David Sobral, Max Gronke, Ana Paulino-Afonso, Mauro
Stefanon, and Huub Röttgering. “Confirmation of Double Peaked Lyα Emission at
z = 6.593: Witnessing a Galaxy Directly Contributing to the Reionisation of the
Universe.” Astronomy & Astrophysics. EDP Sciences, 2018. https://doi.org/10.1051/0004-6361/201833528.'
ieee: 'J. J. Matthee, D. Sobral, M. Gronke, A. Paulino-Afonso, M. Stefanon, and
H. Röttgering, “Confirmation of double peaked Lyα emission at z = 6.593: Witnessing
a galaxy directly contributing to the reionisation of the universe,” Astronomy
& Astrophysics, vol. 619. EDP Sciences, 2018.'
ista: 'Matthee JJ, Sobral D, Gronke M, Paulino-Afonso A, Stefanon M, Röttgering
H. 2018. Confirmation of double peaked Lyα emission at z = 6.593: Witnessing a
galaxy directly contributing to the reionisation of the universe. Astronomy &
Astrophysics. 619, A136.'
mla: 'Matthee, Jorryt J., et al. “Confirmation of Double Peaked Lyα Emission at
z = 6.593: Witnessing a Galaxy Directly Contributing to the Reionisation of the
Universe.” Astronomy & Astrophysics, vol. 619, A136, EDP Sciences,
2018, doi:10.1051/0004-6361/201833528.'
short: J.J. Matthee, D. Sobral, M. Gronke, A. Paulino-Afonso, M. Stefanon, H. Röttgering,
Astronomy & Astrophysics 619 (2018).
date_created: 2022-07-06T11:14:23Z
date_published: 2018-11-19T00:00:00Z
date_updated: 2022-07-19T09:32:08Z
day: '19'
doi: 10.1051/0004-6361/201833528
extern: '1'
external_id:
arxiv:
- '1805.11621'
intvolume: ' 619'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- 'galaxies: high-redshift / galaxies: formation / dark ages / reionization / first
stars / techniques: spectroscopic / intergalactic medium'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1805.11621
month: '11'
oa: 1
oa_version: Published Version
publication: Astronomy & Astrophysics
publication_identifier:
eissn:
- 1432-0746
issn:
- 0004-6361
publication_status: published
publisher: EDP Sciences
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Confirmation of double peaked Lyα emission at z = 6.593: Witnessing a galaxy
directly contributing to the reionisation of the universe'
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 619
year: '2018'
...
---
_id: '11618'
abstract:
- lang: eng
text: Asteroseismology provides global stellar parameters such as masses, radii,
or surface gravities using mean global seismic parameters and effective temperature
for thousands of low-mass stars (0.8 M⊙ < M < 3 M⊙). This methodology has been
successfully applied to stars in which acoustic modes excited by turbulent convection
are measured. Other methods such as the Flicker technique can also be used to
determine stellar surface gravities, but only works for log g above 2.5 dex. In
this work, we present a new metric called FliPer (Flicker in spectral power density,
in opposition to the standard Flicker measurement which is computed in the time
domain); it is able to extend the range for which reliable surface gravities can
be obtained (0.1 < log g < 4.6 dex) without performing any seismic analysis for
stars brighter than Kp < 14. FliPer takes into account the average variability
of a star measured in the power density spectrum in a given range of frequencies.
However, FliPer values calculated on several ranges of frequency are required
to better characterize a star. Using a large set of asteroseismic targets it is
possible to calibrate the behavior of surface gravity with FliPer through machine
learning. This calibration made with a random forest regressor covers a wide range
of surface gravities from main-sequence stars to subgiants and red giants, with
very small uncertainties from 0.04 to 0.1 dex. FliPer values can be inserted in
automatic global seismic pipelines to either give an estimation of the stellar
surface gravity or to assess the quality of the seismic results by detecting any
outliers in the obtained νmax values. FliPer also constrains the surface gravities
of main-sequence dwarfs using only long-cadence data for which the Nyquist frequency
is too low to measure the acoustic-mode properties.
acknowledgement: We thank the anonymous referee for the very useful comments. We would
also like to thank M. Benbakoura for his help in analyzing the light curves of several
binary systems included in our set of stars. L.B. and R.A.G. acknowledge the support
from PLATO and GOLF CNES grants. S.M. acknowledges support from the National Aeronautics
and Space Administration under Grant NNX15AF13G, the National Science Foundation
grant AST-1411685, and the Ramon y Cajal fellowship no. RYC-2015-17697. E.C. is
funded by the European Union’s Horizon 2020 research and innovation program under
the Marie Sklodowska-Curie grant agreement no. 664931. O.J.H and B.M.R. acknowledge
the support of the UK Science and Technology Facilities Council (STFC). Funding
for the Stellar Astrophysics Centre is provided by the Danish National Research
Foundation (Grant DNRF106). This research has made use of NASA’s Astrophysics Data
System. Data presented in this paper were obtained from the Mikulski Archive for
Space Telescopes (MAST). STScI is operated by the Association of Universities for
Research in Astronomy, Inc., under NASA contract NAS5-26555.
article_number: A38
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Lisa Annabelle
full_name: Bugnet, Lisa Annabelle
id: d9edb345-f866-11ec-9b37-d119b5234501
last_name: Bugnet
orcid: 0000-0003-0142-4000
- first_name: R. A.
full_name: García, R. A.
last_name: García
- first_name: G. R.
full_name: Davies, G. R.
last_name: Davies
- first_name: S.
full_name: Mathur, S.
last_name: Mathur
- first_name: E.
full_name: Corsaro, E.
last_name: Corsaro
- first_name: O. J.
full_name: Hall, O. J.
last_name: Hall
- first_name: B. M.
full_name: Rendle, B. M.
last_name: Rendle
citation:
ama: 'Bugnet LA, García RA, Davies GR, et al. FliPer: A global measure of power
density to estimate surface gravities of main-sequence solar-like stars and red
giants. Astronomy & Astrophysics. 2018;620. doi:10.1051/0004-6361/201833106'
apa: 'Bugnet, L. A., García, R. A., Davies, G. R., Mathur, S., Corsaro, E., Hall,
O. J., & Rendle, B. M. (2018). FliPer: A global measure of power density to
estimate surface gravities of main-sequence solar-like stars and red giants. Astronomy
& Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/201833106'
chicago: 'Bugnet, Lisa Annabelle, R. A. García, G. R. Davies, S. Mathur, E. Corsaro,
O. J. Hall, and B. M. Rendle. “FliPer: A Global Measure of Power Density to Estimate
Surface Gravities of Main-Sequence Solar-like Stars and Red Giants.” Astronomy
& Astrophysics. EDP Sciences, 2018. https://doi.org/10.1051/0004-6361/201833106.'
ieee: 'L. A. Bugnet et al., “FliPer: A global measure of power density to
estimate surface gravities of main-sequence solar-like stars and red giants,”
Astronomy & Astrophysics, vol. 620. EDP Sciences, 2018.'
ista: 'Bugnet LA, García RA, Davies GR, Mathur S, Corsaro E, Hall OJ, Rendle BM.
2018. FliPer: A global measure of power density to estimate surface gravities
of main-sequence solar-like stars and red giants. Astronomy & Astrophysics.
620, A38.'
mla: 'Bugnet, Lisa Annabelle, et al. “FliPer: A Global Measure of Power Density
to Estimate Surface Gravities of Main-Sequence Solar-like Stars and Red Giants.”
Astronomy & Astrophysics, vol. 620, A38, EDP Sciences, 2018, doi:10.1051/0004-6361/201833106.'
short: L.A. Bugnet, R.A. García, G.R. Davies, S. Mathur, E. Corsaro, O.J. Hall,
B.M. Rendle, Astronomy & Astrophysics 620 (2018).
date_created: 2022-07-18T14:37:39Z
date_published: 2018-12-01T00:00:00Z
date_updated: 2022-08-22T07:41:07Z
day: '01'
doi: 10.1051/0004-6361/201833106
extern: '1'
external_id:
arxiv:
- '1809.05105'
intvolume: ' 620'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- asteroseismology / methods
- data analysis / stars
- oscillations
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1809.05105
month: '12'
oa: 1
oa_version: Preprint
publication: Astronomy & Astrophysics
publication_identifier:
eissn:
- 1432-0746
issn:
- 0004-6361
publication_status: published
publisher: EDP Sciences
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'FliPer: A global measure of power density to estimate surface gravities of
main-sequence solar-like stars and red giants'
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 620
year: '2018'
...