Colours, star formation rates and environments of star-forming and quiescent galaxies at the cosmic noon
Abstract
We analyse the star formation rates (SFRs), colours and dust extinctions of galaxies in massive (10^(12.5) – 10^(13.5)M⊙) haloes at z ∼ 2 in high-resolution, cosmological zoom-in simulations as part of the Feedback In Realistic Environments (FIRE) project. The simulations do not model feedback from active galactic nuclei (AGNs) but reproduce well the observed relations between stellar and halo mass and between stellar mass and SFR. About half (a third) of the simulated massive galaxies (massive central galaxies) at z ∼ 2 have broad-band colours classifying them as 'quiescent', and the fraction of quiescent centrals is steeply decreasing towards higher redshift, in agreement with observations. The progenitors of z ∼ 2 quiescent central galaxies are, on average, more massive, have lower specific SFRs and reside in more massive haloes than the progenitors of similarly massive star-forming centrals. The simulations further predict a morphological mix of galaxies that includes disc-dominated, irregular and early-type galaxies. However, our simulations do not reproduce the reddest of the quiescent galaxies observed at z ∼ 2. We also do not find evidence for a colour bimodality, but are limited by our modest sample size. In our simulations, the star formation activity of central galaxies of moderate mass (M_(star) ∼ 10^(10) – 10^(11)M⊙) is affected by a combination of two distinct physical processes. Outflows powered by stellar feedback result in a short-lived (<100 Myr), but almost complete, suppression of star formation activity after which many galaxies quickly recover and continue to form stars at normal rates. In addition, galaxies residing in slowly growing haloes tend to experience a moderate reduction of their SFRs ('cosmological starvation'). The relative importance of these processes and AGN feedback is uncertain and will be explored in future work.
Additional Information
© 2017 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. Accepted 2017 May 8. Received 2017 May 4; in original form 2016 October 7. Published: 10 May 2017. RF thanks the referee for suggestions that helped to improve the quality of the paper. RF was supported in part by NASA through Hubble Fellowship grant HF2-51304.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5-26555, in part by the Theoretical Astrophysics Center at UC Berkeley, and by NASA ATP grant 12-ATP-120183. RF also acknowledges financial support from the Swiss National Science Foundation (grant 157591). EQ was supported by NASA ATP grant 12-ATP-120183, a Simons Investigator award from the Simons Foundation, and the David and Lucile Packard Foundation. Support for PFH was provided by an Alfred P. Sloan Research Fellowship, NASA ATP Grant NNX14AH35G, and NSF Collaborative Research Grant 1411920 and CAREER grant 1455342. CAFG was supported by NSF through grants AST-1412836 and AST-1517491, and by NASA through grant NNX15AB22G. DK was supported by NSF grant AST-1412153 and by a Cottrell Scholar Award. Simulations were run with resources provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center, proposal SMD-14-5492. Additional computing support was provided by HEC allocations SMD-14-5189, SMD-15-5950, and NSF XSEDE allocations AST120025, AST150045. This work made extensive use of the NASA Astrophysics Data System and arXiv.org preprint server.Attached Files
Published - stx1120.pdf
Submitted - 1610.02411.pdf
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Additional details
- Eprint ID
- 80836
- Resolver ID
- CaltechAUTHORS:20170828-091308390
- NASA Hubble Fellowship
- HF2-51304.001-A
- NASA
- NAS 5-26555
- UC Berkeley
- NASA
- 12-ATP-120183
- Swiss National Science Foundation (SNSF)
- 157591
- Simons Foundation
- David and Lucile Packard Foundation
- Alfred P. Sloan Foundation
- NASA
- NNX14AH35G
- NSF
- AST-1411920
- NSF
- AST-1455342
- NSF
- AST-1412836
- NSF
- AST-1517491
- NASA
- NNX15AB22G
- NSF
- AST-1412153
- Cottrell Scholar of Research Corporation
- NSF
- AST-120025
- NSF
- AST-150045
- Created
-
2017-08-28Created from EPrint's datestamp field
- Updated
-
2021-11-15Created from EPrint's last_modified field
- Caltech groups
- TAPIR, Astronomy Department