--- _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: '13467' abstract: - lang: eng text: Massive stars are often found in binary systems, and it has been argued that binary products boost the ionizing radiation of stellar populations. Accurate predictions for binary products are needed to understand and quantify their contribution to cosmic reionization. We investigate the contribution of stars stripped in binaries because (1) they are, arguably, the best-understood products of binary evolution, (2) we recently produced the first radiative transfer calculations for the atmospheres of these stripped stars that predict their ionizing spectra, and (3) they are very promising sources because they boost the ionizing emission of stellar populations at late times. This allows stellar feedback to clear the surroundings such that a higher fraction of their photons can escape and ionize the intergalactic medium. Combining our detailed predictions for the ionizing spectra with a simple cosmic reionization model, we estimate that stripped stars contributed tens of percent of the photons that caused cosmic reionization of hydrogen, depending on the assumed escape fractions. More importantly, stripped stars harden the ionizing emission. We estimate that the spectral index for the ionizing part of the spectrum can increase to −1 compared to ≲ − 2 for single stars. At high redshift, stripped stars and massive single stars combined dominate the He II-ionizing emission, but we expect that active galactic nuclei drive cosmic helium reionization. Further observational consequences we expect are (1) high ionization states for the intergalactic gas surrounding stellar systems, such as C IV and Si IV, and (2) additional heating of the intergalactic medium of up to a few thousand Kelvin. Quantifying these warrants the inclusion of accurate models for stripped stars and other binary products in full cosmological simulations. article_number: A134 article_processing_charge: No article_type: original arxiv: 1 author: - 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: S. E. full_name: de Mink, S. E. last_name: de Mink - first_name: M. full_name: McQuinn, M. last_name: McQuinn - first_name: E. full_name: Zapartas, E. last_name: Zapartas - first_name: J. H. full_name: Groh, J. H. last_name: Groh - first_name: C. full_name: Norman, C. last_name: Norman citation: ama: Götberg YLL, de Mink SE, McQuinn M, Zapartas E, Groh JH, Norman C. Contribution from stars stripped in binaries to cosmic reionization of hydrogen and helium. Astronomy & Astrophysics. 2020;634. doi:10.1051/0004-6361/201936669 apa: Götberg, Y. L. L., de Mink, S. E., McQuinn, M., Zapartas, E., Groh, J. H., & Norman, C. (2020). Contribution from stars stripped in binaries to cosmic reionization of hydrogen and helium. Astronomy & Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/201936669 chicago: Götberg, Ylva Louise Linsdotter, S. E. de Mink, M. McQuinn, E. Zapartas, J. H. Groh, and C. Norman. “Contribution from Stars Stripped in Binaries to Cosmic Reionization of Hydrogen and Helium.” Astronomy & Astrophysics. EDP Sciences, 2020. https://doi.org/10.1051/0004-6361/201936669. ieee: Y. L. L. Götberg, S. E. de Mink, M. McQuinn, E. Zapartas, J. H. Groh, and C. Norman, “Contribution from stars stripped in binaries to cosmic reionization of hydrogen and helium,” Astronomy & Astrophysics, vol. 634. EDP Sciences, 2020. ista: Götberg YLL, de Mink SE, McQuinn M, Zapartas E, Groh JH, Norman C. 2020. Contribution from stars stripped in binaries to cosmic reionization of hydrogen and helium. Astronomy & Astrophysics. 634, A134. mla: Götberg, Ylva Louise Linsdotter, et al. “Contribution from Stars Stripped in Binaries to Cosmic Reionization of Hydrogen and Helium.” Astronomy & Astrophysics, vol. 634, A134, EDP Sciences, 2020, doi:10.1051/0004-6361/201936669. short: Y.L.L. Götberg, S.E. de Mink, M. McQuinn, E. Zapartas, J.H. Groh, C. Norman, Astronomy & Astrophysics 634 (2020). date_created: 2023-08-03T10:13:43Z date_published: 2020-02-25T00:00:00Z date_updated: 2023-08-09T12:46:05Z day: '25' doi: 10.1051/0004-6361/201936669 extern: '1' external_id: arxiv: - '1911.00543' intvolume: ' 634' keyword: - Space and Planetary Science - Astronomy and Astrophysics language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1051/0004-6361/201936669 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: Contribution from stars stripped in binaries to cosmic reionization of hydrogen and helium type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 634 year: '2020' ... --- _id: '11499' abstract: - lang: eng text: Deep optical spectroscopic surveys of galaxies provide a unique opportunity to investigate rest-frame ultra-violet (UV) emission line properties of galaxies at z ∼ 2 − 4.5. Here we combine VLT/MUSE Guaranteed Time Observations of the Hubble Deep Field South, Ultra Deep Field, COSMOS, and several quasar fields with other publicly available data from VLT/VIMOS and VLT/FORS2 to construct a catalogue of He II λ1640 emitters at z ≳ 2. The deepest areas of our MUSE pointings reach a 3σ line flux limit of 3.1 × 10−19 erg s−1 cm−2. After discarding broad-line active galactic nuclei, we find 13 He II λ1640 detections from MUSE with a median MUV = −20.1 and 21 tentative He II λ1640 detections from other public surveys. Excluding Lyα, all except two galaxies in our sample show at least one other rest-UV emission line, with C III] λ1907, λ1909 being the most prominent. We use multi-wavelength data available in the Hubble legacy fields to derive basic galaxy properties of our sample through spectral energy distribution fitting techniques. Taking advantage of the high-quality spectra obtained by MUSE (∼10 − 30 h of exposure time per pointing), we use photo-ionisation models to study the rest-UV emission line diagnostics of the He II λ1640 emitters. Line ratios of our sample can be reproduced by moderately sub-solar photo-ionisation models, however, we find that including effects of binary stars lead to degeneracies in most free parameters. Even after considering extra ionising photons produced by extreme sub-solar metallicity binary stellar models, photo-ionisation models are unable to reproduce rest-frame He II λ1640 equivalent widths (∼0.2 − 10 Å), thus additional mechanisms are necessary in models to match the observed He II λ1640 properties. acknowledgement: 'The authors wish to thank the referee for constructive comments that improved the paper substantially. We thank the BPASS team for making the stellar population models available. We thank Elizabeth Stanway, Claus Leitherer, Daniel Schaerer, Jorick Vink, and Nell Byler for insightful discussions. We thank the Lorentz Centre and the scientific organizers of the Characterizing galaxies with spectroscopy with a view for JWST workshop held at the Lorentz Centre in 2017 October, which promoted useful discussions in the wider community. TN, JB, and RB acknowledges the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO) top grant TOP1.16.057. AF acknowledges support from the ERC via an Advanced Grant under grant agreement no. 339659-MUSICOS. JB acknowledges support by Fundação para a Ciência e a Tecnologia (FCT) through national funds (UID/FIS/04434/2013) and Investigador FCT contract IF/01654/2014/CP1215/CT0003, and by FEDER through COMPETE2020 (POCI-01-0145-FEDER-007672). JR acknowledges support from the ERC Starting grant 336736 (CALENDS). This research made use of astropy (http://www.astropy.org) a community-developed core Python package for Astronomy (Astropy Collaboration 2013, 2018) and pandas (McKinney 2010). Figures were generated using matplotlib (Hunter 2007) and seaborn (https://seaborn.pydata.org). Facilities: VLT (MUSE).' article_number: A89 article_processing_charge: No article_type: original arxiv: 1 author: - first_name: Themiya full_name: Nanayakkara, Themiya last_name: Nanayakkara - first_name: Jarle full_name: Brinchmann, Jarle last_name: Brinchmann - first_name: Leindert full_name: Boogaard, Leindert last_name: Boogaard - first_name: Rychard full_name: Bouwens, Rychard last_name: Bouwens - first_name: Sebastiano full_name: Cantalupo, Sebastiano last_name: Cantalupo - first_name: Anna full_name: Feltre, Anna last_name: Feltre - first_name: Wolfram full_name: Kollatschny, Wolfram last_name: Kollatschny - first_name: Raffaella Anna full_name: Marino, Raffaella Anna last_name: Marino - first_name: Michael full_name: Maseda, Michael 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: Mieke full_name: Paalvast, Mieke last_name: Paalvast - first_name: Johan full_name: Richard, Johan last_name: Richard - first_name: Anne full_name: Verhamme, Anne last_name: Verhamme citation: ama: Nanayakkara T, Brinchmann J, Boogaard L, et al. Exploring He II λ1640 emission line properties at z ∼2−4. Astronomy & Astrophysics. 2019;648. doi:10.1051/0004-6361/201834565 apa: Nanayakkara, T., Brinchmann, J., Boogaard, L., Bouwens, R., Cantalupo, S., Feltre, A., … Verhamme, A. (2019). Exploring He II λ1640 emission line properties at z ∼2−4. Astronomy & Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/201834565 chicago: Nanayakkara, Themiya, Jarle Brinchmann, Leindert Boogaard, Rychard Bouwens, Sebastiano Cantalupo, Anna Feltre, Wolfram Kollatschny, et al. “Exploring He II Λ1640 Emission Line Properties at z ∼2−4.” Astronomy & Astrophysics. EDP Sciences, 2019. https://doi.org/10.1051/0004-6361/201834565. ieee: T. Nanayakkara et al., “Exploring He II λ1640 emission line properties at z ∼2−4,” Astronomy & Astrophysics, vol. 648. EDP Sciences, 2019. ista: Nanayakkara T, Brinchmann J, Boogaard L, Bouwens R, Cantalupo S, Feltre A, Kollatschny W, Marino RA, Maseda M, Matthee JJ, Paalvast M, Richard J, Verhamme A. 2019. Exploring He II λ1640 emission line properties at z ∼2−4. Astronomy & Astrophysics. 648, A89. mla: Nanayakkara, Themiya, et al. “Exploring He II Λ1640 Emission Line Properties at z ∼2−4.” Astronomy & Astrophysics, vol. 648, A89, EDP Sciences, 2019, doi:10.1051/0004-6361/201834565. short: T. Nanayakkara, J. Brinchmann, L. Boogaard, R. Bouwens, S. Cantalupo, A. Feltre, W. Kollatschny, R.A. Marino, M. Maseda, J.J. Matthee, M. Paalvast, J. Richard, A. Verhamme, Astronomy & Astrophysics 648 (2019). date_created: 2022-07-06T09:07:06Z date_published: 2019-04-16T00:00:00Z date_updated: 2022-07-19T09:36:08Z day: '16' doi: 10.1051/0004-6361/201834565 extern: '1' external_id: arxiv: - '1902.05960' intvolume: ' 648' keyword: - Space and Planetary Science - Astronomy and Astrophysics - 'galaxies: ISM / galaxies: star formation / galaxies: evolution / galaxies: high-redshift' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1902.05960 month: '04' 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' related_material: link: - relation: erratum url: https://doi.org/10.1051/0004-6361/201834565e scopus_import: '1' status: public title: Exploring He II λ1640 emission line properties at z ∼2−4 type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 648 year: '2019' ... --- _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: '11507' abstract: - lang: eng text: 'Lyman-α (Lyα) is intrinsically the brightest line emitted from active galaxies. While it originates from many physical processes, for star-forming galaxies the intrinsic Lyα luminosity is a direct tracer of the Lyman-continuum (LyC) radiation produced by the most massive O- and early-type B-stars (M⋆ ≳ 10 M⊙) with lifetimes of a few Myrs. As such, Lyα luminosity should be an excellent instantaneous star formation rate (SFR) indicator. However, its resonant nature and susceptibility to dust as a rest-frame UV photon makes Lyα very hard to interpret due to the uncertain Lyα escape fraction, fesc, Lyα. Here we explore results from the CAlibrating LYMan-α with Hα (CALYMHA) survey at z = 2.2, follow-up of Lyα emitters (LAEs) at z = 2.2 − 2.6 and a z ∼ 0−0.3 compilation of LAEs to directly measure fesc, Lyα with Hα. We derive a simple empirical relation that robustly retrieves fesc, Lyα as a function of Lyα rest-frame EW (EW0): fesc,Lyα = 0.0048 EW0[Å] ± 0.05 and we show that it constrains a well-defined anti-correlation between ionisation efficiency (ξion) and dust extinction in LAEs. Observed Lyα luminosities and EW0 are easy measurable quantities at high redshift, thus making our relation a practical tool to estimate intrinsic Lyα and LyC luminosities under well controlled and simple assumptions. Our results allow observed Lyα luminosities to be used to compute SFRs for LAEs at z ∼ 0−2.6 within ±0.2 dex of the Hα dust corrected SFRs. We apply our empirical SFR(Lyα,EW0) calibration to several sources at z ≥ 2.6 to find that star-forming LAEs have SFRs typically ranging from 0.1 to 20 M⊙ yr−1 and that our calibration might be even applicable for the most luminous LAEs within the epoch of re-ionisation. Our results imply high ionisation efficiencies (log10[ξion/Hz erg−1] = 25.4−25.6) and low dust content in LAEs across cosmic time, and will be easily tested with future observations with JWST which can obtain Hα and Hβ measurements for high-redshift LAEs.' acknowledgement: We thank the anonymous referees for multiple comments and suggestions which have improved the manuscript. JM acknowledges the support of a Huygens PhD fellowship from Leiden University. We have benefited greatly from the publicly available programming language PYTHON, including the NUMPY & SCIPY (Van Der Walt et al. 2011; Jones et al. 2001), MATPLOTLIB (Hunter 2007) and ASTROPY (Astropy Collaboration 2013) packages, and the TOPCAT analysis program (Taylor 2013). The results and samples of LAEs used for this paper are publicly available (see e.g. Sobral et al. 2017, 2018a) and we also provide the toy model used as a PYTHON script. article_number: A157 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 citation: ama: 'Sobral D, Matthee JJ. Predicting Lyα escape fractions with a simple observable: Lyα in emission as an empirically calibrated star formation rate indicator. Astronomy & Astrophysics. 2019;623. doi:10.1051/0004-6361/201833075' apa: 'Sobral, D., & Matthee, J. J. (2019). Predicting Lyα escape fractions with a simple observable: Lyα in emission as an empirically calibrated star formation rate indicator. Astronomy & Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/201833075' chicago: 'Sobral, David, and Jorryt J Matthee. “Predicting Lyα Escape Fractions with a Simple Observable: Lyα in Emission as an Empirically Calibrated Star Formation Rate Indicator.” Astronomy & Astrophysics. EDP Sciences, 2019. https://doi.org/10.1051/0004-6361/201833075.' ieee: 'D. Sobral and J. J. Matthee, “Predicting Lyα escape fractions with a simple observable: Lyα in emission as an empirically calibrated star formation rate indicator,” Astronomy & Astrophysics, vol. 623. EDP Sciences, 2019.' ista: 'Sobral D, Matthee JJ. 2019. Predicting Lyα escape fractions with a simple observable: Lyα in emission as an empirically calibrated star formation rate indicator. Astronomy & Astrophysics. 623, A157.' mla: 'Sobral, David, and Jorryt J. Matthee. “Predicting Lyα Escape Fractions with a Simple Observable: Lyα in Emission as an Empirically Calibrated Star Formation Rate Indicator.” Astronomy & Astrophysics, vol. 623, A157, EDP Sciences, 2019, doi:10.1051/0004-6361/201833075.' short: D. Sobral, J.J. Matthee, Astronomy & Astrophysics 623 (2019). date_created: 2022-07-06T11:08:16Z date_published: 2019-03-26T00:00:00Z date_updated: 2022-07-19T09:37:20Z day: '26' doi: 10.1051/0004-6361/201833075 extern: '1' external_id: arxiv: - '1803.08923' intvolume: ' 623' keyword: - Space and Planetary Science - Astronomy and Astrophysics - 'galaxies: high-redshift / galaxies: star formation / galaxies: statistics / galaxies: evolution / galaxies: formation / galaxies: ISM' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1803.08923 month: '03' 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: 'Predicting Lyα escape fractions with a simple observable: Lyα in emission as an empirically calibrated star formation rate indicator' type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 623 year: '2019' ... --- _id: '11614' abstract: - lang: eng text: The NASA Transiting Exoplanet Survey Satellite (TESS) is about to provide full-frame images of almost the entire sky. The amount of stellar data to be analysed represents hundreds of millions stars, which is several orders of magnitude more than the number of stars observed by the Convection, Rotation and planetary Transits satellite (CoRoT), and NASA Kepler and K2 missions. We aim at automatically classifying the newly observed stars with near real-time algorithms to better guide the subsequent detailed studies. In this paper, we present a classification algorithm built to recognise solar-like pulsators among classical pulsators. This algorithm relies on the global amount of power contained in the power spectral density (PSD), also known as the flicker in spectral power density (FliPer). Because each type of pulsating star has a characteristic background or pulsation pattern, the shape of the PSD at different frequencies can be used to characterise the type of pulsating star. The FliPer classifier (FliPerClass) uses different FliPer parameters along with the effective temperature as input parameters to feed a ML algorithm in order to automatically classify the pulsating stars observed by TESS. Using noisy TESS-simulated data from the TESS Asteroseismic Science Consortium (TASC), we classify pulsators with a 98% accuracy. Among them, solar-like pulsating stars are recognised with a 99% accuracy, which is of great interest for a further seismic analysis of these stars, which are like our Sun. Similar results are obtained when we trained our classifier and applied it to 27-day subsets of real Kepler data. FliPerClass is part of the large TASC classification pipeline developed by the TESS Data for Asteroseismology (T’DA) classification working group. acknowledgement: We thank the enitre T’DA team for useful comments and discussions, in particular Andrew Tkachenko. We also acknowledge Marc Hon, Keaton Bell, and James Kuszlewicz for useful comments on the manuscript. L.B. and R.A.G. acknowledge the support from PLATO and GOLF CNES grants. S.M. acknowledges support by the Ramon y Cajal fellowship number RYC-2015-17697. O.J.H. and B.M.R. acknowledge the support of the UK Science and Technology Facilities Council (STFC). M.N.L. acknowledges the support of the ESA PRODEX programme (PEA 4000119301). Funding for the Stellar Astrophysics Centre is provided by the Danish National Research Foundation (Grant DNRF106). article_number: A79 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: S. full_name: Mathur, S. last_name: Mathur - first_name: G. R. full_name: Davies, G. R. last_name: Davies - first_name: O. J. full_name: Hall, O. J. last_name: Hall - first_name: M. N. full_name: Lund, M. N. last_name: Lund - first_name: B. M. full_name: Rendle, B. M. last_name: Rendle citation: ama: 'Bugnet LA, García RA, Mathur S, et al. FliPerClass: In search of solar-like pulsators among TESS targets. Astronomy & Astrophysics. 2019;624. doi:10.1051/0004-6361/201834780' apa: 'Bugnet, L. A., García, R. A., Mathur, S., Davies, G. R., Hall, O. J., Lund, M. N., & Rendle, B. M. (2019). FliPerClass: In search of solar-like pulsators among TESS targets. Astronomy & Astrophysics. EDP Science. https://doi.org/10.1051/0004-6361/201834780' chicago: 'Bugnet, Lisa Annabelle, R. A. García, S. Mathur, G. R. Davies, O. J. Hall, M. N. Lund, and B. M. Rendle. “FliPerClass: In Search of Solar-like Pulsators among TESS Targets.” Astronomy & Astrophysics. EDP Science, 2019. https://doi.org/10.1051/0004-6361/201834780.' ieee: 'L. A. Bugnet et al., “FliPerClass: In search of solar-like pulsators among TESS targets,” Astronomy & Astrophysics, vol. 624. EDP Science, 2019.' ista: 'Bugnet LA, García RA, Mathur S, Davies GR, Hall OJ, Lund MN, Rendle BM. 2019. FliPerClass: In search of solar-like pulsators among TESS targets. Astronomy & Astrophysics. 624, A79.' mla: 'Bugnet, Lisa Annabelle, et al. “FliPerClass: In Search of Solar-like Pulsators among TESS Targets.” Astronomy & Astrophysics, vol. 624, A79, EDP Science, 2019, doi:10.1051/0004-6361/201834780.' short: L.A. Bugnet, R.A. García, S. Mathur, G.R. Davies, O.J. Hall, M.N. Lund, B.M. Rendle, Astronomy & Astrophysics 624 (2019). date_created: 2022-07-18T14:13:34Z date_published: 2019-04-19T00:00:00Z date_updated: 2022-08-22T07:32:51Z day: '19' doi: 10.1051/0004-6361/201834780 extern: '1' external_id: arxiv: - '1902.09854' intvolume: ' 624' keyword: - Space and Planetary Science - Astronomy and Astrophysics language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1902.09854 month: '04' oa: 1 oa_version: Preprint publication: Astronomy & Astrophysics publication_identifier: eissn: - 1432-0746 issn: - 0004-6361 publication_status: published publisher: EDP Science quality_controlled: '1' scopus_import: '1' status: public title: 'FliPerClass: In search of solar-like pulsators among TESS targets' type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 624 year: '2019' ... --- _id: '13468' abstract: - lang: eng text: Hydrogen-rich supernovae, known as Type II (SNe II), are the most common class of explosions observed following the collapse of the core of massive stars. We used analytical estimates and population synthesis simulations to assess the fraction of SNe II progenitors that are expected to have exchanged mass with a companion prior to explosion. We estimate that 1/3 to 1/2 of SN II progenitors have a history of mass exchange with a binary companion before exploding. The dominant binary channels leading to SN II progenitors involve the merger of binary stars. Mergers are expected to produce a diversity of SN II progenitor characteristics, depending on the evolutionary timing and properties of the merger. Alternatively, SN II progenitors from interacting binaries may have accreted mass from their companion, and subsequently been ejected from the binary system after their companion exploded. We show that the overall fraction of SN II progenitors that are predicted to have experienced binary interaction is robust against the main physical uncertainties in our models. However, the relative importance of different binary evolutionary channels is affected by changing physical assumptions. We further discuss ways in which binarity might contribute to the observed diversity of SNe II by considering potential observational signatures arising from each binary channel. For supernovae which have a substantial H-rich envelope at explosion (i.e., excluding Type IIb SNe), a surviving non-compact companion would typically indicate that the supernova progenitor star was in a wide, non-interacting binary. We argue that a significant fraction of even Type II-P SNe are expected to have gained mass from a companion prior to explosion. article_number: A5 article_processing_charge: No article_type: original arxiv: 1 author: - first_name: Emmanouil full_name: Zapartas, Emmanouil last_name: Zapartas - first_name: Selma E. full_name: de Mink, Selma E. last_name: de Mink - first_name: Stephen full_name: Justham, Stephen last_name: Justham - first_name: Nathan full_name: Smith, Nathan last_name: Smith - first_name: Alex full_name: de Koter, Alex last_name: de Koter - first_name: Mathieu full_name: Renzo, Mathieu last_name: Renzo - first_name: Iair full_name: Arcavi, Iair last_name: Arcavi - first_name: Rob full_name: Farmer, Rob last_name: Farmer - 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: Silvia full_name: Toonen, Silvia last_name: Toonen citation: ama: 'Zapartas E, de Mink SE, Justham S, et al. The diverse lives of progenitors of hydrogen-rich core-collapse supernovae: The role of binary interaction. Astronomy & Astrophysics. 2019;631. doi:10.1051/0004-6361/201935854' apa: 'Zapartas, E., de Mink, S. E., Justham, S., Smith, N., de Koter, A., Renzo, M., … Toonen, S. (2019). The diverse lives of progenitors of hydrogen-rich core-collapse supernovae: The role of binary interaction. Astronomy & Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/201935854' chicago: 'Zapartas, Emmanouil, Selma E. de Mink, Stephen Justham, Nathan Smith, Alex de Koter, Mathieu Renzo, Iair Arcavi, Rob Farmer, Ylva Louise Linsdotter Götberg, and Silvia Toonen. “The Diverse Lives of Progenitors of Hydrogen-Rich Core-Collapse Supernovae: The Role of Binary Interaction.” Astronomy & Astrophysics. EDP Sciences, 2019. https://doi.org/10.1051/0004-6361/201935854.' ieee: 'E. Zapartas et al., “The diverse lives of progenitors of hydrogen-rich core-collapse supernovae: The role of binary interaction,” Astronomy & Astrophysics, vol. 631. EDP Sciences, 2019.' ista: 'Zapartas E, de Mink SE, Justham S, Smith N, de Koter A, Renzo M, Arcavi I, Farmer R, Götberg YLL, Toonen S. 2019. The diverse lives of progenitors of hydrogen-rich core-collapse supernovae: The role of binary interaction. Astronomy & Astrophysics. 631, A5.' mla: 'Zapartas, Emmanouil, et al. “The Diverse Lives of Progenitors of Hydrogen-Rich Core-Collapse Supernovae: The Role of Binary Interaction.” Astronomy & Astrophysics, vol. 631, A5, EDP Sciences, 2019, doi:10.1051/0004-6361/201935854.' short: E. Zapartas, S.E. de Mink, S. Justham, N. Smith, A. de Koter, M. Renzo, I. Arcavi, R. Farmer, Y.L.L. Götberg, S. Toonen, Astronomy & Astrophysics 631 (2019). date_created: 2023-08-03T10:13:52Z date_published: 2019-11-20T00:00:00Z date_updated: 2023-08-09T12:36:09Z day: '20' doi: 10.1051/0004-6361/201935854 extern: '1' external_id: arxiv: - '1907.06687' intvolume: ' 631' keyword: - Space and Planetary Science - Astronomy and Astrophysics language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1051/0004-6361/201935854 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: 'The diverse lives of progenitors of hydrogen-rich core-collapse supernovae: The role of binary interaction' type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 631 year: '2019' ... --- _id: '13469' abstract: - lang: eng text: Stars stripped of their envelopes from interaction with a binary companion emit a significant fraction of their radiation as ionizing photons. They are potentially important stellar sources of ionizing radiation, however, they are still often neglected in spectral synthesis simulations or simulations of stellar feedback. In anticipating the large datasets of galaxy spectra from the upcoming James Webb Space Telescope, we modeled the radiative contribution from stripped stars by using detailed evolutionary and spectral models. We estimated their impact on the integrated spectra and specifically on the emission rates of H I-, He I-, and He II-ionizing photons from stellar populations. We find that stripped stars have the largest impact on the ionizing spectrum of a population in which star formation halted several Myr ago. In such stellar populations, stripped stars dominate the emission of ionizing photons, mimicking a younger stellar population in which massive stars are still present. Our models also suggest that stripped stars have harder ionizing spectra than massive stars. The additional ionizing radiation, with which stripped stars contribute affects observable properties that are related to the emission of ionizing photons from stellar populations. In co-eval stellar populations, the ionizing radiation from stripped stars increases the ionization parameter and the production efficiency of hydrogen ionizing photons. They also cause high values for these parameters for about ten times longer than what is predicted for massive stars. The effect on properties related to non-ionizing wavelengths is less pronounced, such as on the ultraviolet continuum slope or stellar contribution to emission lines. However, the hard ionizing radiation from stripped stars likely introduces a characteristic ionization structure of the nebula, which leads to the emission of highly ionized elements such as O2+ and C3+. We, therefore, expect that the presence of stripped stars affects the location in the BPT diagram and the diagnostic ratio of O III to O II nebular emission lines. Our models are publicly available through CDS database and on the STARBURST99 website. article_number: A134 article_processing_charge: No article_type: original arxiv: 1 author: - 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: S. E. full_name: de Mink, S. E. last_name: de Mink - first_name: J. H. full_name: Groh, J. H. last_name: Groh - first_name: C. full_name: Leitherer, C. last_name: Leitherer - first_name: C. full_name: Norman, C. last_name: Norman citation: ama: Götberg YLL, de Mink SE, Groh JH, Leitherer C, Norman C. The impact of stars stripped in binaries on the integrated spectra of stellar populations. Astronomy & Astrophysics. 2019;629. doi:10.1051/0004-6361/201834525 apa: Götberg, Y. L. L., de Mink, S. E., Groh, J. H., Leitherer, C., & Norman, C. (2019). The impact of stars stripped in binaries on the integrated spectra of stellar populations. Astronomy & Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/201834525 chicago: Götberg, Ylva Louise Linsdotter, S. E. de Mink, J. H. Groh, C. Leitherer, and C. Norman. “The Impact of Stars Stripped in Binaries on the Integrated Spectra of Stellar Populations.” Astronomy & Astrophysics. EDP Sciences, 2019. https://doi.org/10.1051/0004-6361/201834525. ieee: Y. L. L. Götberg, S. E. de Mink, J. H. Groh, C. Leitherer, and C. Norman, “The impact of stars stripped in binaries on the integrated spectra of stellar populations,” Astronomy & Astrophysics, vol. 629. EDP Sciences, 2019. ista: Götberg YLL, de Mink SE, Groh JH, Leitherer C, Norman C. 2019. The impact of stars stripped in binaries on the integrated spectra of stellar populations. Astronomy & Astrophysics. 629, A134. mla: Götberg, Ylva Louise Linsdotter, et al. “The Impact of Stars Stripped in Binaries on the Integrated Spectra of Stellar Populations.” Astronomy & Astrophysics, vol. 629, A134, EDP Sciences, 2019, doi:10.1051/0004-6361/201834525. short: Y.L.L. Götberg, S.E. de Mink, J.H. Groh, C. Leitherer, C. Norman, Astronomy & Astrophysics 629 (2019). date_created: 2023-08-03T10:14:00Z date_published: 2019-09-17T00:00:00Z date_updated: 2023-08-09T12:34:11Z day: '17' doi: 10.1051/0004-6361/201834525 extern: '1' external_id: arxiv: - '1908.06102' intvolume: ' 629' keyword: - Space and Planetary Science - Astronomy and Astrophysics language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1051/0004-6361/201834525 month: '09' 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 impact of stars stripped in binaries on the integrated spectra of stellar populations type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 629 year: '2019' ... --- _id: '13470' abstract: - lang: eng text: "Context. Massive Wolf–Rayet (WR) stars dominate the radiative and mechanical energy budget of galaxies and probe a critical phase in the evolution of massive stars prior to core collapse. It is not known whether core He-burning WR stars (classical WR; cWR) form predominantly through wind stripping (w-WR) or binary stripping (b-WR). Whereas spectroscopy of WR binaries has so-far largely been avoided because of its complexity, our study focuses on the 44 WR binaries and binary candidates of the Large Magellanic Cloud (LMC; metallicity Z ≈ 0.5 Z⊙), which were identified on the basis of radial velocity variations, composite spectra, or high X-ray luminosities.\r\n\r\nAims. Relying on a diverse spectroscopic database, we aim to derive the physical and orbital parameters of our targets, confronting evolution models of evolved massive stars at subsolar metallicity and constraining the impact of binary interaction in forming these stars.\r\n\r\nMethods. Spectroscopy was performed using the Potsdam Wolf–Rayet (PoWR) code and cross-correlation techniques. Disentanglement was performed using the code Spectangular or the shift-and-add algorithm. Evolutionary status was interpreted using the Binary Population and Spectral Synthesis (BPASS) code, exploring binary interaction and chemically homogeneous evolution.\r\n\r\nResults. Among our sample, 28/44 objects show composite spectra and are analyzed as such. An additional five targets show periodically moving WR primaries but no detected companions (SB1); two (BAT99 99 and 112) are potential WR + compact-object candidates owing to their high X-ray luminosities. We cannot confirm the binary nature of the remaining 11 candidates. About two-thirds of the WN components in binaries are identified as cWR, and one-third as hydrogen-burning WR stars. We establish metallicity-dependent mass-loss recipes, which broadly agree with those recently derived for single WN stars, and in which so-called WN3/O3 stars are clear outliers. We estimate that 45  ±  30% of the cWR stars in our sample have interacted with a companion via mass transfer. However, only ≈12  ±  7% of the cWR stars in our sample naively appear to have formed purely owing to stripping via a companion (12% b-WR). Assuming that apparently single WR stars truly formed as single stars, this comprises ≈4% of the whole LMC WN population, which is about ten times less than expected. No obvious differences in the properties of single and binary WN stars, whose luminosities extend down to log L ≈ 5.2 [L⊙], are apparent. With the exception of a few systems (BAT99 19, 49, and 103), the equatorial rotational velocities of the OB-type companions are moderate (veq ≲ 250 km s−1) and challenge standard formalisms of angular-momentum accretion. For most objects, chemically homogeneous evolution can be rejected for the secondary, but not for the WR progenitor.\r\n\r\nConclusions. No obvious dichotomy in the locations of apparently single and binary WN stars on the Hertzsprung-Russell diagram is apparent. According to commonly used stellar evolution models (BPASS, Geneva), most apparently single WN stars could not have formed as single stars, implying that they were stripped by an undetected companion. Otherwise, it must follow that pre-WR mass-loss/mixing (e.g., during the red supergiant phase) are strongly underestimated in standard stellar evolution models." article_number: A151 article_processing_charge: No article_type: original author: - first_name: T. full_name: Shenar, T. last_name: Shenar - first_name: D. P. full_name: Sablowski, D. P. last_name: Sablowski - first_name: R. full_name: Hainich, R. last_name: Hainich - first_name: H. full_name: Todt, H. last_name: Todt - first_name: A. F. J. full_name: Moffat, A. F. J. last_name: Moffat - first_name: L. M. full_name: Oskinova, L. M. last_name: Oskinova - first_name: V. full_name: Ramachandran, V. last_name: Ramachandran - first_name: H. full_name: Sana, H. last_name: Sana - first_name: A. A. C. full_name: Sander, A. A. C. last_name: Sander - first_name: O. full_name: Schnurr, O. last_name: Schnurr - first_name: N. full_name: St-Louis, N. last_name: St-Louis - first_name: D. full_name: Vanbeveren, D. last_name: Vanbeveren - 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: W.-R. full_name: Hamann, W.-R. last_name: Hamann citation: ama: Shenar T, Sablowski DP, Hainich R, et al. The Wolf–Rayet binaries of the nitrogen sequence in the Large Magellanic Cloud. Astronomy & Astrophysics. 2019;627. doi:10.1051/0004-6361/201935684 apa: Shenar, T., Sablowski, D. P., Hainich, R., Todt, H., Moffat, A. F. J., Oskinova, L. M., … Hamann, W.-R. (2019). The Wolf–Rayet binaries of the nitrogen sequence in the Large Magellanic Cloud. Astronomy & Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/201935684 chicago: Shenar, T., D. P. Sablowski, R. Hainich, H. Todt, A. F. J. Moffat, L. M. Oskinova, V. Ramachandran, et al. “The Wolf–Rayet Binaries of the Nitrogen Sequence in the Large Magellanic Cloud.” Astronomy & Astrophysics. EDP Sciences, 2019. https://doi.org/10.1051/0004-6361/201935684. ieee: T. Shenar et al., “The Wolf–Rayet binaries of the nitrogen sequence in the Large Magellanic Cloud,” Astronomy & Astrophysics, vol. 627. EDP Sciences, 2019. ista: Shenar T, Sablowski DP, Hainich R, Todt H, Moffat AFJ, Oskinova LM, Ramachandran V, Sana H, Sander AAC, Schnurr O, St-Louis N, Vanbeveren D, Götberg YLL, Hamann W-R. 2019. The Wolf–Rayet binaries of the nitrogen sequence in the Large Magellanic Cloud. Astronomy & Astrophysics. 627, A151. mla: Shenar, T., et al. “The Wolf–Rayet Binaries of the Nitrogen Sequence in the Large Magellanic Cloud.” Astronomy & Astrophysics, vol. 627, A151, EDP Sciences, 2019, doi:10.1051/0004-6361/201935684. short: T. Shenar, D.P. Sablowski, R. Hainich, H. Todt, A.F.J. Moffat, L.M. Oskinova, V. Ramachandran, H. Sana, A.A.C. Sander, O. Schnurr, N. St-Louis, D. Vanbeveren, Y.L.L. Götberg, W.-R. Hamann, Astronomy & Astrophysics 627 (2019). date_created: 2023-08-03T10:14:09Z date_published: 2019-07-16T00:00:00Z date_updated: 2023-08-09T12:29:58Z day: '16' doi: 10.1051/0004-6361/201935684 extern: '1' intvolume: ' 627' keyword: - Space and Planetary Science - Astronomy and Astrophysics language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1051/0004-6361/201935684 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' related_material: link: - relation: erratum url: https://doi.org/10.1051/0004-6361/201935684e scopus_import: '1' status: public title: The Wolf–Rayet binaries of the nitrogen sequence in the Large Magellanic Cloud type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 627 year: '2019' ... --- _id: '13471' abstract: - lang: eng text: We perform an extensive numerical study of the evolution of massive binary systems to predict the peculiar velocities that stars obtain when their companion collapses and disrupts the system. Our aim is to (i) identify which predictions are robust against model uncertainties and assess their implications, (ii) investigate which physical processes leave a clear imprint and may therefore be constrained observationally, and (iii) provide a suite of publicly available model predictions to allow for the use of kinematic constraints from the Gaia mission. We find that 22+26−8% of all massive binary systems merge prior to the first core-collapse in the system. Of the remainder, 86+11−9% become unbound because of the core-collapse. Remarkably, this rarely produces runaway stars (observationally defined as stars with velocities above 30 km s−1). These are outnumbered by more than an order of magnitude by slower unbound companions, or “walkaway stars”. This is a robust outcome of our simulations and is due to the reversal of the mass ratio prior to the explosion and widening of the orbit, as we show analytically and numerically. For stars more massive than 15 M⊙, we estimate that 10+5−8% are walkaways and only 0.5+1.0−0.4% are runaways, nearly all of which have accreted mass from their companion. Our findings are consistent with earlier studies; however, the low runaway fraction we find is in tension with observed fractions of about 10%. Thus, astrometric data on presently single massive stars can potentially constrain the physics of massive binary evolution. Finally, we show that the high end of the mass distributions of runaway stars is very sensitive to the assumed black hole natal kicks, and we propose this as a potentially stringent test for the explosion mechanism. We also discuss companions remaining bound that can evolve into X-ray and gravitational wave sources. article_number: A66 article_processing_charge: No article_type: original arxiv: 1 author: - first_name: M. full_name: Renzo, M. last_name: Renzo - first_name: E. full_name: Zapartas, E. last_name: Zapartas - first_name: S. E. full_name: de Mink, S. E. last_name: de Mink - 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: S. full_name: Justham, S. last_name: Justham - first_name: R. J. full_name: Farmer, R. J. last_name: Farmer - first_name: R. G. full_name: Izzard, R. G. last_name: Izzard - first_name: S. full_name: Toonen, S. last_name: Toonen - first_name: H. full_name: Sana, H. last_name: Sana citation: ama: Renzo M, Zapartas E, de Mink SE, et al. Massive runaway and walkaway stars. Astronomy & Astrophysics. 2019;624. doi:10.1051/0004-6361/201833297 apa: Renzo, M., Zapartas, E., de Mink, S. E., Götberg, Y. L. L., Justham, S., Farmer, R. J., … Sana, H. (2019). Massive runaway and walkaway stars. Astronomy & Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/201833297 chicago: Renzo, M., E. Zapartas, S. E. de Mink, Ylva Louise Linsdotter Götberg, S. Justham, R. J. Farmer, R. G. Izzard, S. Toonen, and H. Sana. “Massive Runaway and Walkaway Stars.” Astronomy & Astrophysics. EDP Sciences, 2019. https://doi.org/10.1051/0004-6361/201833297. ieee: M. Renzo et al., “Massive runaway and walkaway stars,” Astronomy & Astrophysics, vol. 624. EDP Sciences, 2019. ista: Renzo M, Zapartas E, de Mink SE, Götberg YLL, Justham S, Farmer RJ, Izzard RG, Toonen S, Sana H. 2019. Massive runaway and walkaway stars. Astronomy & Astrophysics. 624, A66. mla: Renzo, M., et al. “Massive Runaway and Walkaway Stars.” Astronomy & Astrophysics, vol. 624, A66, EDP Sciences, 2019, doi:10.1051/0004-6361/201833297. short: M. Renzo, E. Zapartas, S.E. de Mink, Y.L.L. Götberg, S. Justham, R.J. Farmer, R.G. Izzard, S. Toonen, H. Sana, Astronomy & Astrophysics 624 (2019). date_created: 2023-08-03T10:14:18Z date_published: 2019-04-11T00:00:00Z date_updated: 2023-08-09T12:26:08Z day: '11' doi: 10.1051/0004-6361/201833297 extern: '1' external_id: arxiv: - '1804.09164' intvolume: ' 624' keyword: - Space and Planetary Science - Astronomy and Astrophysics language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1051/0004-6361/201833297 month: '04' 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: Massive runaway and walkaway stars type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 624 year: '2019' ... --- _id: '13472' abstract: - lang: eng text: Massive stars in binaries can give rise to extreme phenomena such as X-ray binaries and gravitational wave sources after one or both stars end their lives as core-collapse supernovae. Stars in close orbit around a stellar or compact companion are expected to explode as “stripped-envelope supernovae”, showing no (Type Ib/c) or little (Type IIb) signs of hydrogen in the spectra, because hydrogen-rich progenitors are too large to fit. The physical processes responsible for the stripping process and the fate of the companion are still very poorly understood. Aiming to find new clues, we investigate Cas A, which is a very young (∼340 yr) and near (∼3.4 kpc) remnant of a core-collapse supernova. Cas A has been subject to several searches for possible companions, all unsuccessfully. We present new measurements of the proper motions and photometry of stars in the vicinity based on deep HST ACS/WFC and WFC3-IR data. We identify stellar sources that are close enough in projection but using their proper motions we show that none are compatible with being at the location of center at the time of explosion, in agreement with earlier findings. Our photometric measurements allow us to place much deeper (order-of-magnitude) upper limits on the brightness of possible undetected companions. We systematically compare them with model predictions for a wide variety of scenarios. We can confidently rule out the presence of any stellar companion of any reasonable mass and age (main sequence, pre main sequence or stripped) ruling out what many considered to be likely evolutionary scenarios for Type IIb supernova (SN IIb). More exotic scenarios that predict the presence of a compact companion (white dwarf, neutron star or black hole) are still possible as well as scenarios where the progenitor of Cas A was single at the moment of explosion (either because it was truly single, or resulted from a binary that was disrupted, or from a binary merger). The presence of a compact companion would imply that Cas A is of interest to study exotic outcomes of binary evolution. The single-at-death solution would still require fine-tuning of the process that removed most of the envelope through a mass-loss mechanism yet to be identified. We discuss how future constraints from Gaia and even deeper photometric studies may help to place further constraints. article_number: A34 article_processing_charge: No article_type: original arxiv: 1 author: - first_name: Wolfgang E. full_name: Kerzendorf, Wolfgang E. last_name: Kerzendorf - first_name: Tuan full_name: Do, Tuan last_name: Do - first_name: Selma E. full_name: de Mink, Selma E. last_name: de Mink - 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: Dan full_name: Milisavljevic, Dan last_name: Milisavljevic - first_name: Emmanouil full_name: Zapartas, Emmanouil last_name: Zapartas - first_name: Mathieu full_name: Renzo, Mathieu last_name: Renzo - first_name: Stephen full_name: Justham, Stephen last_name: Justham - first_name: Philipp full_name: Podsiadlowski, Philipp last_name: Podsiadlowski - first_name: Robert A. full_name: Fesen, Robert A. last_name: Fesen citation: ama: Kerzendorf WE, Do T, de Mink SE, et al. No surviving non-compact stellar companion to Cassiopeia A. Astronomy & Astrophysics. 2019;623. doi:10.1051/0004-6361/201732206 apa: Kerzendorf, W. E., Do, T., de Mink, S. E., Götberg, Y. L. L., Milisavljevic, D., Zapartas, E., … Fesen, R. A. (2019). No surviving non-compact stellar companion to Cassiopeia A. Astronomy & Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/201732206 chicago: Kerzendorf, Wolfgang E., Tuan Do, Selma E. de Mink, Ylva Louise Linsdotter Götberg, Dan Milisavljevic, Emmanouil Zapartas, Mathieu Renzo, Stephen Justham, Philipp Podsiadlowski, and Robert A. Fesen. “No Surviving Non-Compact Stellar Companion to Cassiopeia A.” Astronomy & Astrophysics. EDP Sciences, 2019. https://doi.org/10.1051/0004-6361/201732206. ieee: W. E. Kerzendorf et al., “No surviving non-compact stellar companion to Cassiopeia A,” Astronomy & Astrophysics, vol. 623. EDP Sciences, 2019. ista: Kerzendorf WE, Do T, de Mink SE, Götberg YLL, Milisavljevic D, Zapartas E, Renzo M, Justham S, Podsiadlowski P, Fesen RA. 2019. No surviving non-compact stellar companion to Cassiopeia A. Astronomy & Astrophysics. 623, A34. mla: Kerzendorf, Wolfgang E., et al. “No Surviving Non-Compact Stellar Companion to Cassiopeia A.” Astronomy & Astrophysics, vol. 623, A34, EDP Sciences, 2019, doi:10.1051/0004-6361/201732206. short: W.E. Kerzendorf, T. Do, S.E. de Mink, Y.L.L. Götberg, D. Milisavljevic, E. Zapartas, M. Renzo, S. Justham, P. Podsiadlowski, R.A. Fesen, Astronomy & Astrophysics 623 (2019). date_created: 2023-08-03T10:14:27Z date_published: 2019-03-27T00:00:00Z date_updated: 2023-08-09T12:28:17Z day: '27' doi: 10.1051/0004-6361/201732206 extern: '1' external_id: arxiv: - '1711.00055' intvolume: ' 623' keyword: - Space and Planetary Science - Astronomy and Astrophysics language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1051/0004-6361/201732206 month: '03' 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: No surviving non-compact stellar companion to Cassiopeia A type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 623 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' ... --- _id: '11619' abstract: - lang: eng text: We report on the confirmation and mass determination of π Men c, the first transiting planet discovered by NASA’s TESS space mission. π Men is a naked-eye (V = 5.65 mag), quiet G0 V star that was previously known to host a sub-stellar companion (π Men b) on a longperiod (Porb = 2091 days), eccentric (e = 0.64) orbit. Using TESS time-series photometry, combined with Gaia data, published UCLES at AAT Doppler measurements, and archival HARPS at ESO-3.6m radial velocities, we found that π Men c is a close-in planet with an orbital period of Porb = 6.27 days, a mass of Mc = 4.52 ± 0.81 M⊕, and a radius of Rc = 2.06 ± 0.03 R⊕. Based on the planet’s orbital period and size, π Men c is a super-Earth located at, or close to, the radius gap, while its mass and bulk density suggest it may have held on to a significant atmosphere. Because of the brightness of the host star, this system is highly suitable for a wide range of further studies to characterize the planetary atmosphere and dynamical properties. We also performed an asteroseismic analysis of the TESS data and detected a hint of power excess consistent with the seismic values expected for this star, although this result depends on the photometric aperture used to extract the light curve. This marginal detection is expected from pre-launch simulations hinting at the asteroseismic potential of the TESS mission for longer, multi-sector observations and/or for more evolved bright stars. article_number: L10 article_processing_charge: No article_type: letter_note arxiv: 1 author: - first_name: D. full_name: Gandolfi, D. last_name: Gandolfi - first_name: O. full_name: Barragán, O. last_name: Barragán - first_name: J. H. full_name: Livingston, J. H. last_name: Livingston - first_name: M. full_name: Fridlund, M. last_name: Fridlund - first_name: A. B. full_name: Justesen, A. B. last_name: Justesen - first_name: S. full_name: Redfield, S. last_name: Redfield - first_name: L. full_name: Fossati, L. last_name: Fossati - first_name: S. full_name: Mathur, S. last_name: Mathur - first_name: S. full_name: Grziwa, S. last_name: Grziwa - first_name: J. full_name: Cabrera, J. last_name: Cabrera - first_name: R. A. full_name: García, R. A. last_name: García - first_name: C. M. full_name: Persson, C. M. last_name: Persson - first_name: V. full_name: Van Eylen, V. last_name: Van Eylen - first_name: A. P. full_name: Hatzes, A. P. last_name: Hatzes - first_name: D. full_name: Hidalgo, D. last_name: Hidalgo - first_name: S. full_name: Albrecht, S. last_name: Albrecht - 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: W. D. full_name: Cochran, W. D. last_name: Cochran - first_name: Sz. full_name: Csizmadia, Sz. last_name: Csizmadia - first_name: H. full_name: Deeg, H. last_name: Deeg - first_name: Ph. full_name: Eigmüller, Ph. last_name: Eigmüller - first_name: M. full_name: Endl, M. last_name: Endl - first_name: A. full_name: Erikson, A. last_name: Erikson - first_name: M. full_name: Esposito, M. last_name: Esposito - first_name: E. full_name: Guenther, E. last_name: Guenther - first_name: J. full_name: Korth, J. last_name: Korth - first_name: R. full_name: Luque, R. last_name: Luque - first_name: P. full_name: Montañes Rodríguez, P. last_name: Montañes Rodríguez - first_name: D. full_name: Nespral, D. last_name: Nespral - first_name: G. full_name: Nowak, G. last_name: Nowak - first_name: M. full_name: Pätzold, M. last_name: Pätzold - first_name: J. full_name: Prieto-Arranz, J. last_name: Prieto-Arranz citation: ama: 'Gandolfi D, Barragán O, Livingston JH, et al. TESS’s first planet: A super-Earth transiting the naked-eye star π Mensae. Astronomy & Astrophysics. 2018;619. doi:10.1051/0004-6361/201834289' apa: 'Gandolfi, D., Barragán, O., Livingston, J. H., Fridlund, M., Justesen, A. B., Redfield, S., … Prieto-Arranz, J. (2018). TESS’s first planet: A super-Earth transiting the naked-eye star π Mensae. Astronomy & Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/201834289' chicago: 'Gandolfi, D., O. Barragán, J. H. Livingston, M. Fridlund, A. B. Justesen, S. Redfield, L. Fossati, et al. “TESS’s First Planet: A Super-Earth Transiting the Naked-Eye Star π Mensae.” Astronomy & Astrophysics. EDP Sciences, 2018. https://doi.org/10.1051/0004-6361/201834289.' ieee: 'D. Gandolfi et al., “TESS’s first planet: A super-Earth transiting the naked-eye star π Mensae,” Astronomy & Astrophysics, vol. 619. EDP Sciences, 2018.' ista: 'Gandolfi D, Barragán O, Livingston JH, Fridlund M, Justesen AB, Redfield S, Fossati L, Mathur S, Grziwa S, Cabrera J, García RA, Persson CM, Van Eylen V, Hatzes AP, Hidalgo D, Albrecht S, Bugnet LA, Cochran WD, Csizmadia S, Deeg H, Eigmüller P, Endl M, Erikson A, Esposito M, Guenther E, Korth J, Luque R, Montañes Rodríguez P, Nespral D, Nowak G, Pätzold M, Prieto-Arranz J. 2018. TESS’s first planet: A super-Earth transiting the naked-eye star π Mensae. Astronomy & Astrophysics. 619, L10.' mla: 'Gandolfi, D., et al. “TESS’s First Planet: A Super-Earth Transiting the Naked-Eye Star π Mensae.” Astronomy & Astrophysics, vol. 619, L10, EDP Sciences, 2018, doi:10.1051/0004-6361/201834289.' short: D. Gandolfi, O. Barragán, J.H. Livingston, M. Fridlund, A.B. Justesen, S. Redfield, L. Fossati, S. Mathur, S. Grziwa, J. Cabrera, R.A. García, C.M. Persson, V. Van Eylen, A.P. Hatzes, D. Hidalgo, S. Albrecht, L.A. Bugnet, W.D. Cochran, S. Csizmadia, H. Deeg, P. Eigmüller, M. Endl, A. Erikson, M. Esposito, E. Guenther, J. Korth, R. Luque, P. Montañes Rodríguez, D. Nespral, G. Nowak, M. Pätzold, J. Prieto-Arranz, Astronomy & Astrophysics 619 (2018). date_created: 2022-07-18T14:41:16Z date_published: 2018-11-22T00:00:00Z date_updated: 2022-08-22T07:43:29Z day: '22' doi: 10.1051/0004-6361/201834289 extern: '1' external_id: arxiv: - '1809.07573' intvolume: ' 619' keyword: - Space and Planetary Science - Astronomy and Astrophysics - planetary systems / planets and satellites - detection / planets and satellites - fundamental parameters / planets and satellites - terrestrial planets / stars - fundamental parameters language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1809.07573 month: '11' 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: 'TESS’s first planet: A super-Earth transiting the naked-eye star π Mensae' type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 619 year: '2018' ... --- _id: '13473' abstract: - lang: eng text: Stripped-envelope stars form in binary systems after losing mass through Roche-lobe overflow. They bear astrophysical significance as sources of UV and ionizing radiation in older stellar populations and, if sufficiently massive, as stripped supernova progenitors. Binary evolutionary models predict that they are common, but only a handful of subdwarfs with B-type companions are known. The question is whether a large population of such systems has evaded detection as a result of biases, or whether the model predictions are wrong. We reanalyze the well-studied post-interaction binary φ Persei. Recently, new data have improved the orbital solution of the system, which contains an ~1.2M⊙ stripped-envelope star and a rapidly rotating ~9.6M⊙ Be star. We compare with an extensive grid of evolutionary models using a Bayesian approach and constrain the initial masses of the progenitor to 7.2 ± 0.4M⊙ for the stripped star and 3.8 ± 0.4M⊙ for the Be star. The system must have evolved through near-conservative mass transfer. These findings are consistent with earlier studies. The age we obtain, 57 ± 9 Myr, is in excellent agreement with the age of the α Persei cluster. We note that neither star was initially massive enough to produce a core-collapse supernova, but mass exchange pushed the Be star above the mass threshold. We find that the subdwarf is overluminous for its mass by almost an order of magnitude, compared to the expectations for a helium core burning star. We can only reconcile this if the subdwarf resides in a late phase of helium shell burning, which lasts only 2–3% of the total lifetime as a subdwarf. Assuming continuous star formation implies that up to ~50 less evolved, dimmer subdwarfs exist for each system similar to φ Persei, but have evaded detection so far. Our findings can be interpreted as a strong indication that a substantial population of stripped-envelope stars indeed exists, but has so far evaded detection because of observational biases and lack of large-scale systematic searches. article_number: A30 article_processing_charge: No article_type: original arxiv: 1 author: - first_name: A. full_name: Schootemeijer, A. last_name: Schootemeijer - 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: S. E. full_name: de Mink, S. E. last_name: de Mink - first_name: D. full_name: Gies, D. last_name: Gies - first_name: E. full_name: Zapartas, E. last_name: Zapartas citation: ama: Schootemeijer A, Götberg YLL, de Mink SE, Gies D, Zapartas E. Clues about the scarcity of stripped-envelope stars from the evolutionary state of the sdO+Be binary system φ Persei. Astronomy & Astrophysics. 2018;615. doi:10.1051/0004-6361/201731194 apa: Schootemeijer, A., Götberg, Y. L. L., de Mink, S. E., Gies, D., & Zapartas, E. (2018). Clues about the scarcity of stripped-envelope stars from the evolutionary state of the sdO+Be binary system φ Persei. Astronomy & Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/201731194 chicago: Schootemeijer, A., Ylva Louise Linsdotter Götberg, S. E. de Mink, D. Gies, and E. Zapartas. “Clues about the Scarcity of Stripped-Envelope Stars from the Evolutionary State of the SdO+Be Binary System φ Persei.” Astronomy & Astrophysics. EDP Sciences, 2018. https://doi.org/10.1051/0004-6361/201731194. ieee: A. Schootemeijer, Y. L. L. Götberg, S. E. de Mink, D. Gies, and E. Zapartas, “Clues about the scarcity of stripped-envelope stars from the evolutionary state of the sdO+Be binary system φ Persei,” Astronomy & Astrophysics, vol. 615. EDP Sciences, 2018. ista: Schootemeijer A, Götberg YLL, de Mink SE, Gies D, Zapartas E. 2018. Clues about the scarcity of stripped-envelope stars from the evolutionary state of the sdO+Be binary system φ Persei. Astronomy & Astrophysics. 615, A30. mla: Schootemeijer, A., et al. “Clues about the Scarcity of Stripped-Envelope Stars from the Evolutionary State of the SdO+Be Binary System φ Persei.” Astronomy & Astrophysics, vol. 615, A30, EDP Sciences, 2018, doi:10.1051/0004-6361/201731194. short: A. Schootemeijer, Y.L.L. Götberg, S.E. de Mink, D. Gies, E. Zapartas, Astronomy & Astrophysics 615 (2018). date_created: 2023-08-03T10:14:37Z date_published: 2018-07-06T00:00:00Z date_updated: 2023-08-09T12:22:52Z day: '06' doi: 10.1051/0004-6361/201731194 extern: '1' external_id: arxiv: - '1803.02379' intvolume: ' 615' keyword: - Space and Planetary Science - Astronomy and Astrophysics language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1051/0004-6361/201731194 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: Clues about the scarcity of stripped-envelope stars from the evolutionary state of the sdO+Be binary system φ Persei type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 615 year: '2018' ... --- _id: '13475' abstract: - lang: eng text: Stars stripped of their hydrogen-rich envelope through interaction with a binary companion are generally not considered when accounting for ionizing radiation from stellar populations, despite the expectation that stripped stars emit hard ionizing radiation, form frequently, and live 10–100 times longer than single massive stars. We compute the first grid of evolutionary and spectral models specially made for stars stripped in binaries for a range of progenitor masses (2–20 M⊙) and metallicities ranging from solar to values representative for pop II stars. For stripped stars with masses in the range 0.3–7 M⊙, we find consistently high effective temperatures (20 000–100 000 K, increasing with mass), small radii (0.2–1 R⊙), and high bolometric luminosities, comparable to that of their progenitor before stripping. The spectra show a continuous sequence that naturally bridges subdwarf-type stars at the low-mass end and Wolf-Rayet-like spectra at the high-mass end. For intermediate masses we find hybrid spectral classes showing a mixture of absorption and emission lines. These appear for stars with mass-loss rates of 10−8−10−6 M⊙ yr−1, which have semi-transparent atmospheres. At low metallicity, substantial hydrogen-rich layers are left at the surface and we predict spectra that resemble O-type stars instead. We obtain spectra undistinguishable from subdwarfs for stripped stars with masses up to 1.7 M⊙, which questions whether the widely adopted canonical value of 0.47 M⊙ is uniformly valid. Only a handful of stripped stars of intermediate mass have currently been identified observationally. Increasing this sample will provide necessary tests for the physics of interaction, internal mixing, and stellar winds. We use our model spectra to investigate the feasibility to detect stripped stars next to an optically bright companion and recommend systematic searches for their UV excess and possible emission lines, most notably HeII λ4686 in the optical and HeII λ1640 in the UV. Our models are publicly available for further investigations or inclusion in spectral synthesis simulations. article_number: A78 article_processing_charge: No article_type: original arxiv: 1 author: - 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: S. E. full_name: de Mink, S. E. last_name: de Mink - first_name: J. H. full_name: Groh, J. H. last_name: Groh - first_name: T. full_name: Kupfer, T. last_name: Kupfer - first_name: P. A. full_name: Crowther, P. A. last_name: Crowther - first_name: E. full_name: Zapartas, E. last_name: Zapartas - first_name: M. full_name: Renzo, M. last_name: Renzo citation: ama: 'Götberg YLL, de Mink SE, Groh JH, et al. Spectral models for binary products: Unifying subdwarfs and Wolf-Rayet stars as a sequence of stripped-envelope stars. Astronomy &amp; Astrophysics. 2018;615. doi:10.1051/0004-6361/201732274' apa: 'Götberg, Y. L. L., de Mink, S. E., Groh, J. H., Kupfer, T., Crowther, P. A., Zapartas, E., & Renzo, M. (2018). Spectral models for binary products: Unifying subdwarfs and Wolf-Rayet stars as a sequence of stripped-envelope stars. Astronomy &amp; Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/201732274' chicago: 'Götberg, Ylva Louise Linsdotter, S. E. de Mink, J. H. Groh, T. Kupfer, P. A. Crowther, E. Zapartas, and M. Renzo. “Spectral Models for Binary Products: Unifying Subdwarfs and Wolf-Rayet Stars as a Sequence of Stripped-Envelope Stars.” Astronomy &amp; Astrophysics. EDP Sciences, 2018. https://doi.org/10.1051/0004-6361/201732274.' ieee: 'Y. L. L. Götberg et al., “Spectral models for binary products: Unifying subdwarfs and Wolf-Rayet stars as a sequence of stripped-envelope stars,” Astronomy &amp; Astrophysics, vol. 615. EDP Sciences, 2018.' ista: 'Götberg YLL, de Mink SE, Groh JH, Kupfer T, Crowther PA, Zapartas E, Renzo M. 2018. Spectral models for binary products: Unifying subdwarfs and Wolf-Rayet stars as a sequence of stripped-envelope stars. Astronomy &amp; Astrophysics. 615, A78.' mla: 'Götberg, Ylva Louise Linsdotter, et al. “Spectral Models for Binary Products: Unifying Subdwarfs and Wolf-Rayet Stars as a Sequence of Stripped-Envelope Stars.” Astronomy &amp; Astrophysics, vol. 615, A78, EDP Sciences, 2018, doi:10.1051/0004-6361/201732274.' short: Y.L.L. Götberg, S.E. de Mink, J.H. Groh, T. Kupfer, P.A. Crowther, E. Zapartas, M. Renzo, Astronomy &amp; Astrophysics 615 (2018). date_created: 2023-08-03T10:15:00Z date_published: 2018-07-17T00:00:00Z date_updated: 2023-08-09T11:22:17Z day: '17' doi: 10.1051/0004-6361/201732274 extern: '1' external_id: arxiv: - '1802.03018' intvolume: ' 615' keyword: - Space and Planetary Science - Astronomy and Astrophysics language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1051/0004-6361/201732274 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: 'Spectral models for binary products: Unifying subdwarfs and Wolf-Rayet stars as a sequence of stripped-envelope stars' type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 615 year: '2018' ... --- _id: '13476' abstract: - lang: eng text: Understanding ionizing fluxes of stellar populations is crucial for various astrophysical problems including the epoch of reionization. Short-lived massive stars are generally considered as the main stellar sources. We examine the potential role of less massive stars that lose their envelope through interaction with a binary companion. Here, we focus on the role of metallicity (Z). For this purpose we used the evolutionary code MESA and created tailored atmosphere models with the radiative transfer code CMFGEN. We show that typical progenitors, with initial masses of 12 M⊙, produce hot and compact stars (~ 4 M⊙, 60–80 kK, ~1 R⊙). These stripped stars copiously produce ionizing photons, emitting 60–85% and 30–60% of their energy as HI and HeI ionizing radiation, for Z = 0.0001–0.02, respectively. Their output is comparable to what massive stars emit during their Wolf-Rayet phase, if we account for their longer lifetimes and the favorable slope of the initial mass function. Their relative importance for reionization may be further favored since they emit their photons with a time delay (~ 20 Myr after birth in our fiducial model). This allows time for the dispersal of the birth clouds, allowing the ionizing photons to escape into the intergalactic medium. At low Z, we find that Roche stripping fails to fully remove the H-rich envelope, because of the reduced opacity in the subsurface layers. This is in sharp contrast with the assumption of complete stripping that is made in rapid population synthesis simulations, which are widely used to simulate the binary progenitors of supernovae and gravitational waves. Finally, we discuss the urgency to increase the observed sample of stripped stars to test these models and we discuss how our predictions can help to design efficient observational campaigns. article_number: A11 article_processing_charge: No article_type: original arxiv: 1 author: - 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: S. E. full_name: de Mink, S. E. last_name: de Mink - first_name: J. H. full_name: Groh, J. H. last_name: Groh citation: ama: 'Götberg YLL, de Mink SE, Groh JH. Ionizing spectra of stars that lose their envelope through interaction with a binary companion: Role of metallicity. Astronomy & Astrophysics. 2017;608. doi:10.1051/0004-6361/201730472' apa: 'Götberg, Y. L. L., de Mink, S. E., & Groh, J. H. (2017). Ionizing spectra of stars that lose their envelope through interaction with a binary companion: Role of metallicity. Astronomy & Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/201730472' chicago: 'Götberg, Ylva Louise Linsdotter, S. E. de Mink, and J. H. Groh. “Ionizing Spectra of Stars That Lose Their Envelope through Interaction with a Binary Companion: Role of Metallicity.” Astronomy & Astrophysics. EDP Sciences, 2017. https://doi.org/10.1051/0004-6361/201730472.' ieee: 'Y. L. L. Götberg, S. E. de Mink, and J. H. Groh, “Ionizing spectra of stars that lose their envelope through interaction with a binary companion: Role of metallicity,” Astronomy & Astrophysics, vol. 608. EDP Sciences, 2017.' ista: 'Götberg YLL, de Mink SE, Groh JH. 2017. Ionizing spectra of stars that lose their envelope through interaction with a binary companion: Role of metallicity. Astronomy & Astrophysics. 608, A11.' mla: 'Götberg, Ylva Louise Linsdotter, et al. “Ionizing Spectra of Stars That Lose Their Envelope through Interaction with a Binary Companion: Role of Metallicity.” Astronomy & Astrophysics, vol. 608, A11, EDP Sciences, 2017, doi:10.1051/0004-6361/201730472.' short: Y.L.L. Götberg, S.E. de Mink, J.H. Groh, Astronomy & Astrophysics 608 (2017). date_created: 2023-08-03T10:15:09Z date_published: 2017-12-01T00:00:00Z date_updated: 2023-08-09T11:27:06Z day: '01' doi: 10.1051/0004-6361/201730472 extern: '1' external_id: arxiv: - '1701.07439' intvolume: ' 608' keyword: - Space and Planetary Science - Astronomy and Astrophysics language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1051/0004-6361/201730472 month: '12' 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: 'Ionizing spectra of stars that lose their envelope through interaction with a binary companion: Role of metallicity' type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 608 year: '2017' ... --- _id: '13477' abstract: - lang: eng text: Most massive stars, the progenitors of core-collapse supernovae, are in close binary systems and may interact with their companion through mass transfer or merging. We undertake a population synthesis study to compute the delay-time distribution of core-collapse supernovae, that is, the supernova rate versus time following a starburst, taking into account binary interactions. We test the systematic robustness of our results by running various simulations to account for the uncertainties in our standard assumptions. We find that a significant fraction, 15+9-8%, of core-collapse supernovae are “late”, that is, they occur 50–200 Myr after birth, when all massive single stars have already exploded. These late events originate predominantly from binary systems with at least one, or, in most cases, with both stars initially being of intermediate mass (4–8 M⊙). The main evolutionary channels that contribute often involve either the merging of the initially more massive primary star with its companion or the engulfment of the remaining core of the primary by the expanding secondary that has accreted mass at an earlier evolutionary stage. Also, the total number of core-collapse supernovae increases by 14+15-14% because of binarity for the same initial stellar mass. The high rate implies that we should have already observed such late core-collapse supernovae, but have not recognized them as such. We argue that φ Persei is a likely progenitor and that eccentric neutron star – white dwarf systems are likely descendants. Late events can help explain the discrepancy in the delay-time distributions derived from supernova remnants in the Magellanic Clouds and extragalactic type Ia events, lowering the contribution of prompt Ia events. We discuss ways to test these predictions and speculate on the implications for supernova feedback in simulations of galaxy evolution. article_number: A29 article_processing_charge: No article_type: original arxiv: 1 author: - first_name: E. full_name: Zapartas, E. last_name: Zapartas - first_name: S. E. full_name: de Mink, S. E. last_name: de Mink - first_name: R. G. full_name: Izzard, R. G. last_name: Izzard - first_name: S.-C. full_name: Yoon, S.-C. last_name: Yoon - first_name: C. full_name: Badenes, C. last_name: Badenes - 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: A. full_name: de Koter, A. last_name: de Koter - first_name: C. J. full_name: Neijssel, C. J. last_name: Neijssel - first_name: M. full_name: Renzo, M. last_name: Renzo - first_name: A. full_name: Schootemeijer, A. last_name: Schootemeijer - first_name: T. S. full_name: Shrotriya, T. S. last_name: Shrotriya citation: ama: Zapartas E, de Mink SE, Izzard RG, et al. Delay-time distribution of core-collapse supernovae with late events resulting from binary interaction. Astronomy & Astrophysics. 2017;601(A&A). doi:10.1051/0004-6361/201629685 apa: Zapartas, E., de Mink, S. E., Izzard, R. G., Yoon, S.-C., Badenes, C., Götberg, Y. L. L., … Shrotriya, T. S. (2017). Delay-time distribution of core-collapse supernovae with late events resulting from binary interaction. Astronomy & Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/201629685 chicago: Zapartas, E., S. E. de Mink, R. G. Izzard, S.-C. Yoon, C. Badenes, Ylva Louise Linsdotter Götberg, A. de Koter, et al. “Delay-Time Distribution of Core-Collapse Supernovae with Late Events Resulting from Binary Interaction.” Astronomy & Astrophysics. EDP Sciences, 2017. https://doi.org/10.1051/0004-6361/201629685. ieee: E. Zapartas et al., “Delay-time distribution of core-collapse supernovae with late events resulting from binary interaction,” Astronomy & Astrophysics, vol. 601, no. A&A. EDP Sciences, 2017. ista: Zapartas E, de Mink SE, Izzard RG, Yoon S-C, Badenes C, Götberg YLL, de Koter A, Neijssel CJ, Renzo M, Schootemeijer A, Shrotriya TS. 2017. Delay-time distribution of core-collapse supernovae with late events resulting from binary interaction. Astronomy & Astrophysics. 601(A&A), A29. mla: Zapartas, E., et al. “Delay-Time Distribution of Core-Collapse Supernovae with Late Events Resulting from Binary Interaction.” Astronomy & Astrophysics, vol. 601, no. A&A, A29, EDP Sciences, 2017, doi:10.1051/0004-6361/201629685. short: E. Zapartas, S.E. de Mink, R.G. Izzard, S.-C. Yoon, C. Badenes, Y.L.L. Götberg, A. de Koter, C.J. Neijssel, M. Renzo, A. Schootemeijer, T.S. Shrotriya, Astronomy & Astrophysics 601 (2017). date_created: 2023-08-03T10:15:18Z date_published: 2017-05-01T00:00:00Z date_updated: 2023-08-09T11:15:49Z day: '01' doi: 10.1051/0004-6361/201629685 extern: '1' external_id: arxiv: - '1701.07032' intvolume: ' 601' issue: A&A keyword: - Space and Planetary Science - Astronomy and Astrophysics language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1051/0004-6361/201629685 month: '05' 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: Delay-time distribution of core-collapse supernovae with late events resulting from binary interaction type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 601 year: '2017' ... --- _id: '13478' abstract: - lang: eng text: HR 8799 is a star accompanied by four massive planets on wide orbits. The observed planetary configuration has been shown to be unstable on a timescale much shorter than the estimated age of the system (~30 Myr) unless the planets are locked into mean motion resonances. This condition is characterised by small-amplitude libration of one or more resonant angles that stabilise the system by preventing close encounters. We simulate planetary systems similar to the HR 8799 planetary system, exploring the parameter space in separation between the orbits, planetary masses and distance from the Sun to the star. We find systems that look like HR 8799 and remain stable for longer than the estimated age of HR 8799. None of our systems are forced into resonances. We find, with nominal masses (Mb = 5 MJup and Mc,d,e = 7 MJup) and in a narrow range of orbit separations, that 5 of 100 systems match the observations and lifetime. Considering a broad range of orbit separations, we find 12 of 900 similar systems. The systems survive significantly longer because of their slightly increased initial orbit separations compared to assuming circular orbits from the observed positions. A small increase in separation leads to a significant increase in survival time. The low eccentricity the orbits develop from gravitational interaction is enough for the planets to match the observations. With lower masses, but still comfortably within the estimated planet mass uncertainty, we find 18 of 100 matching and long-lived systems in a narrow orbital separation range. In the broad separation range, we find 82 of 900 matching systems. Our results imply that the planets in the HR 8799 system do not have to be in strong mean motion resonances. We also investigate the future of wide-orbit planetary systems using our HR 8799 analogues. We find that 80% of the systems have two planets left after strong planet-planet scattering and these are on eccentric orbits with semi-major axes of a1 ~ 10 AU and a2 ~ 30−1000 AU. We speculate that other wide-orbit planetary systems, such as AB Pic and HD 106906, are the remnants of HR 8799 analogues that underwent close encounters and dynamical instability. article_number: A147 article_processing_charge: No article_type: original arxiv: 1 author: - 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: Melvyn B. full_name: Davies, Melvyn B. last_name: Davies - first_name: Alexander J. full_name: Mustill, Alexander J. last_name: Mustill - first_name: Anders full_name: Johansen, Anders last_name: Johansen - first_name: Ross P. full_name: Church, Ross P. last_name: Church citation: ama: Götberg YLL, Davies MB, Mustill AJ, Johansen A, Church RP. Long-term stability of the HR 8799 planetary system without resonant lock. Astronomy & Astrophysics. 2016;592. doi:10.1051/0004-6361/201526309 apa: Götberg, Y. L. L., Davies, M. B., Mustill, A. J., Johansen, A., & Church, R. P. (2016). Long-term stability of the HR 8799 planetary system without resonant lock. Astronomy & Astrophysics. EDP Sciences. https://doi.org/10.1051/0004-6361/201526309 chicago: Götberg, Ylva Louise Linsdotter, Melvyn B. Davies, Alexander J. Mustill, Anders Johansen, and Ross P. Church. “Long-Term Stability of the HR 8799 Planetary System without Resonant Lock.” Astronomy & Astrophysics. EDP Sciences, 2016. https://doi.org/10.1051/0004-6361/201526309. ieee: Y. L. L. Götberg, M. B. Davies, A. J. Mustill, A. Johansen, and R. P. Church, “Long-term stability of the HR 8799 planetary system without resonant lock,” Astronomy & Astrophysics, vol. 592. EDP Sciences, 2016. ista: Götberg YLL, Davies MB, Mustill AJ, Johansen A, Church RP. 2016. Long-term stability of the HR 8799 planetary system without resonant lock. Astronomy & Astrophysics. 592, A147. mla: Götberg, Ylva Louise Linsdotter, et al. “Long-Term Stability of the HR 8799 Planetary System without Resonant Lock.” Astronomy & Astrophysics, vol. 592, A147, EDP Sciences, 2016, doi:10.1051/0004-6361/201526309. short: Y.L.L. Götberg, M.B. Davies, A.J. Mustill, A. Johansen, R.P. Church, Astronomy & Astrophysics 592 (2016). date_created: 2023-08-03T10:15:28Z date_published: 2016-08-18T00:00:00Z date_updated: 2023-08-09T11:09:50Z day: '18' doi: 10.1051/0004-6361/201526309 extern: '1' external_id: arxiv: - '1606.07819' intvolume: ' 592' keyword: - Space and Planetary Science - Astronomy and Astrophysics language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1051/0004-6361/201526309 month: '08' 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: Long-term stability of the HR 8799 planetary system without resonant lock type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 592 year: '2016' ...