---
_id: '11540'
abstract:
- lang: eng
  text: Observations have revealed that the star formation rate (SFR) and stellar
    mass (Mstar) of star-forming galaxies follow a tight relation known as the galaxy
    main sequence. However, what physical information is encoded in this relation
    is under debate. Here, we use the EAGLE cosmological hydrodynamical simulation
    to study the mass dependence, evolution, and origin of scatter in the SFR–Mstar
    relation. At z = 0, we find that the scatter decreases slightly with stellar mass
    from 0.35 dex at Mstar ≈ 109 M⊙ to 0.30 dex at Mstar ≳ 1010.5 M⊙. The scatter
    decreases from z = 0 to z = 5 by 0.05 dex at Mstar ≳ 1010 M⊙ and by 0.15 dex for
    lower masses. We show that the scatter at z = 0.1 originates from a combination
    of fluctuations on short time-scales (ranging from 0.2–2 Gyr) that are presumably
    associated with self-regulation from cooling, star formation, and outflows, but
    is dominated by long time-scale (∼10 Gyr) variations related to differences in
    halo formation times. Shorter time-scale fluctuations are relatively more important
    for lower mass galaxies. At high masses, differences in black hole formation efficiency
    cause additional scatter, but also diminish the scatter caused by different halo
    formation times. While individual galaxies cross the main sequence multiple times
    during their evolution, they fluctuate around tracks associated with their halo
    properties, i.e. galaxies above/below the main sequence at z = 0.1 tend to have
    been above/below the main sequence for ≫1 Gyr.
acknowledgement: JM acknowledges the support of a Huygens PhD fellowship from Leiden
  University. We thank Camila Correa for help analysing snipshot merger trees. We
  thank the anonymous referee for constructive comments. We also thank Jarle Brinchmann,
  Rob Crain, Antonios Katsianis, Paola Popesso, and David Sobral for discussions and
  suggestions. We also thank the participants of the Lorentz Center workshop ‘A Decade
  of the Star-Forming Main Sequence’ held on 2017 September 4–8, for discussions and
  ideas. We have benefited from the public available programming language PYTHON,
  including the NUMPY, MATPLOTLIB, and SCIPY (Hunter 2007) packages and the TOPCAT
  analysis tool (Taylor 2013).
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Jorryt J
  full_name: Matthee, Jorryt J
  id: 7439a258-f3c0-11ec-9501-9df22fe06720
  last_name: Matthee
  orcid: 0000-0003-2871-127X
- first_name: Joop
  full_name: Schaye, Joop
  last_name: Schaye
citation:
  ama: Matthee JJ, Schaye J. The origin of scatter in the star formation rate–stellar
    mass relation. <i>Monthly Notices of the Royal Astronomical Society</i>. 2019;484(1):915-932.
    doi:<a href="https://doi.org/10.1093/mnras/stz030">10.1093/mnras/stz030</a>
  apa: Matthee, J. J., &#38; Schaye, J. (2019). The origin of scatter in the star
    formation rate–stellar mass relation. <i>Monthly Notices of the Royal Astronomical
    Society</i>. Oxford University Press. <a href="https://doi.org/10.1093/mnras/stz030">https://doi.org/10.1093/mnras/stz030</a>
  chicago: Matthee, Jorryt J, and Joop Schaye. “The Origin of Scatter in the Star
    Formation Rate–Stellar Mass Relation.” <i>Monthly Notices of the Royal Astronomical
    Society</i>. Oxford University Press, 2019. <a href="https://doi.org/10.1093/mnras/stz030">https://doi.org/10.1093/mnras/stz030</a>.
  ieee: J. J. Matthee and J. Schaye, “The origin of scatter in the star formation
    rate–stellar mass relation,” <i>Monthly Notices of the Royal Astronomical Society</i>,
    vol. 484, no. 1. Oxford University Press, pp. 915–932, 2019.
  ista: Matthee JJ, Schaye J. 2019. The origin of scatter in the star formation rate–stellar
    mass relation. Monthly Notices of the Royal Astronomical Society. 484(1), 915–932.
  mla: Matthee, Jorryt J., and Joop Schaye. “The Origin of Scatter in the Star Formation
    Rate–Stellar Mass Relation.” <i>Monthly Notices of the Royal Astronomical Society</i>,
    vol. 484, no. 1, Oxford University Press, 2019, pp. 915–32, doi:<a href="https://doi.org/10.1093/mnras/stz030">10.1093/mnras/stz030</a>.
  short: J.J. Matthee, J. Schaye, Monthly Notices of the Royal Astronomical Society
    484 (2019) 915–932.
date_created: 2022-07-08T07:48:31Z
date_published: 2019-03-01T00:00:00Z
date_updated: 2022-08-19T06:42:43Z
day: '01'
doi: 10.1093/mnras/stz030
extern: '1'
external_id:
  arxiv:
  - '1805.05956'
intvolume: '       484'
issue: '1'
keyword:
- Space and Planetary Science
- 'Astronomy and Astrophysics : galaxies: evolution'
- 'galaxies: formation'
- 'galaxies: star formation'
- 'cosmology: theory'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/1805.05956
month: '03'
oa: 1
oa_version: Preprint
page: 915-932
publication: Monthly Notices of the Royal Astronomical Society
publication_identifier:
  eissn:
  - 1365-2966
  issn:
  - 0035-8711
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: The origin of scatter in the star formation rate–stellar mass relation
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 484
year: '2019'
...
---
_id: '11565'
abstract:
- lang: eng
  text: We use the hydrodynamical EAGLE simulation to study the magnitude and origin
    of the scatter in the stellar mass–halo mass relation for central galaxies. We
    separate cause and effect by correlating stellar masses in the baryonic simulation
    with halo properties in a matched dark matter only (DMO) simulation. The scatter
    in stellar mass increases with redshift and decreases with halo mass. At z = 0.1,
    it declines from 0.25 dex at M200, DMO ≈ 1011 M⊙ to 0.12 dex at M200, DMO ≈ 1013
    M⊙, but the trend is weak above 1012 M⊙. For M200, DMO < 1012.5 M⊙ up to 0.04
    dex of the scatter is due to scatter in the halo concentration. At fixed halo
    mass, a larger stellar mass corresponds to a more concentrated halo. This is likely
    because higher concentrations imply earlier formation times and hence more time
    for accretion and star formation, and/or because feedback is less efficient in
    haloes with higher binding energies. The maximum circular velocity, Vmax, DMO,
    and binding energy are therefore more fundamental properties than halo mass, meaning
    that they are more accurate predictors of stellar mass, and we provide fitting
    formulae for their relations with stellar mass. However, concentration alone cannot
    explain the total scatter in the Mstar−M200,DMO relation, and it does not explain
    the scatter in Mstar–Vmax, DMO. Halo spin, sphericity, triaxiality, substructure
    and environment are also not responsible for the remaining scatter, which thus
    could be due to more complex halo properties or non-linear/stochastic baryonic
    effects.
acknowledgement: We thank the anonymous referee for their comments. JM acknowledges
  the support of a Huygens PhD fellowship from Leiden University. JM thanks David
  Sobral for useful discussions and help with fitting routines and Jonas Chavez Montero
  and Ying Zu for providing data. We thank PRACE for the access to the Curie facility
  in France. We have used the DiRAC system which is a part of National E-Infrastructure
  at Durham University, operated by the Institute for Computational Cosmology on behalf
  of the STFC DiRAC HPC Facility (www.dirac.ac.uk); the equipment was funded by BIS
  National E-infrastructure capital grant ST/K00042X/1, STFC capital grant ST/H008519/1,
  STFC DiRAC Operations grant ST/K003267/1 and Durham University. The study was sponsored
  by the Dutch National Computing Facilities Foundation (NCF) for the use of supercomputer
  facilities, with financial support from the Netherlands Organisation for Scientific
  Research (NWO), through VICI grant 639.043.409, and the European Research Council
  under the European Union’s Seventh Framework Programme (FP7/2007-2013)/ERC Grant
  agreement 278594- GasAroundGalaxies, and from the Belgian Science Policy Office
  ([AP P7/08 CHARM]). We have benefited greatly from the public available programming
  language PYTHON, including the NUMPY, MATPLOTLIB, PYFITS, SCIPY, H5PY and RPY2 packages,
  and the TOPCAT analysis program (Taylor 2005).
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: Joop
  full_name: Schaye, Joop
  last_name: Schaye
- first_name: Robert A.
  full_name: Crain, Robert A.
  last_name: Crain
- first_name: Matthieu
  full_name: Schaller, Matthieu
  last_name: Schaller
- first_name: Richard
  full_name: Bower, Richard
  last_name: Bower
- first_name: Tom
  full_name: Theuns, Tom
  last_name: Theuns
citation:
  ama: Matthee JJ, Schaye J, Crain RA, Schaller M, Bower R, Theuns T. The origin of
    scatter in the stellar mass–halo mass relation of central galaxies in the EAGLE
    simulation. <i>Monthly Notices of the Royal Astronomical Society</i>. 2017;465(2):2381-2396.
    doi:<a href="https://doi.org/10.1093/mnras/stw2884">10.1093/mnras/stw2884</a>
  apa: Matthee, J. J., Schaye, J., Crain, R. A., Schaller, M., Bower, R., &#38; Theuns,
    T. (2017). The origin of scatter in the stellar mass–halo mass relation of central
    galaxies in the EAGLE simulation. <i>Monthly Notices of the Royal Astronomical
    Society</i>. Oxford University Press. <a href="https://doi.org/10.1093/mnras/stw2884">https://doi.org/10.1093/mnras/stw2884</a>
  chicago: Matthee, Jorryt J, Joop Schaye, Robert A. Crain, Matthieu Schaller, Richard
    Bower, and Tom Theuns. “The Origin of Scatter in the Stellar Mass–Halo Mass Relation
    of Central Galaxies in the EAGLE Simulation.” <i>Monthly Notices of the Royal
    Astronomical Society</i>. Oxford University Press, 2017. <a href="https://doi.org/10.1093/mnras/stw2884">https://doi.org/10.1093/mnras/stw2884</a>.
  ieee: J. J. Matthee, J. Schaye, R. A. Crain, M. Schaller, R. Bower, and T. Theuns,
    “The origin of scatter in the stellar mass–halo mass relation of central galaxies
    in the EAGLE simulation,” <i>Monthly Notices of the Royal Astronomical Society</i>,
    vol. 465, no. 2. Oxford University Press, pp. 2381–2396, 2017.
  ista: Matthee JJ, Schaye J, Crain RA, Schaller M, Bower R, Theuns T. 2017. The origin
    of scatter in the stellar mass–halo mass relation of central galaxies in the EAGLE
    simulation. Monthly Notices of the Royal Astronomical Society. 465(2), 2381–2396.
  mla: Matthee, Jorryt J., et al. “The Origin of Scatter in the Stellar Mass–Halo
    Mass Relation of Central Galaxies in the EAGLE Simulation.” <i>Monthly Notices
    of the Royal Astronomical Society</i>, vol. 465, no. 2, Oxford University Press,
    2017, pp. 2381–96, doi:<a href="https://doi.org/10.1093/mnras/stw2884">10.1093/mnras/stw2884</a>.
  short: J.J. Matthee, J. Schaye, R.A. Crain, M. Schaller, R. Bower, T. Theuns, Monthly
    Notices of the Royal Astronomical Society 465 (2017) 2381–2396.
date_created: 2022-07-12T12:25:08Z
date_published: 2017-02-01T00:00:00Z
date_updated: 2022-08-19T07:56:07Z
day: '01'
doi: 10.1093/mnras/stw2884
extern: '1'
external_id:
  arxiv:
  - '1608.08218'
intvolume: '       465'
issue: '2'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
- 'galaxies: evolution'
- 'galaxies: formation'
- 'galaxies: haloes'
- 'cosmology: theory'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/1608.08218
month: '02'
oa: 1
oa_version: Preprint
page: 2381-2396
publication: Monthly Notices of the Royal Astronomical Society
publication_identifier:
  eissn:
  - 1365-2966
  issn:
  - 0035-8711
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: The origin of scatter in the stellar mass–halo mass relation of central galaxies
  in the EAGLE simulation
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 465
year: '2017'
...