Zfire: Similar stellar growth in hα-emitting cluster and field galaxies at z ∼ 2
Article
Article Title | Zfire: Similar stellar growth in hα-emitting cluster and field galaxies at z ∼ 2 |
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ERA Journal ID | 1057 |
Article Category | Article |
Authors | Tran, Kim-Vy H., Alcorn, Leo Y., Kacprzak, Glenn G., Nanayakkara, Themiya, Straatman, Caroline, Yuan, Tiantian, Cowley, Michael, Davé, Romeel, Glazebrook, Karl, Kewley, Lisa J., Labbé, Ivo, Martizzi, Davidé, Papovich, Casey, Quadri, Ryan, Spitler, Lee R. and Tomczak, Adam |
Journal Title | The Astrophysical Journal: an international review of astronomy and astronomical physics |
Journal Citation | 834 (2), pp. 1-14 |
Article Number | 101 |
Number of Pages | 14 |
Year | 2017 |
Publisher | IOP Publishing |
Place of Publication | United States |
ISSN | 0004-637X |
1538-4357 | |
Digital Object Identifier (DOI) | https://doi.org/10.3847/1538-4357/834/2/101 |
Web Address (URL) | https://iopscience.iop.org/article/10.3847/1538-4357/834/2/101 |
Abstract | We compare galaxy scaling relations as a function of environment at z ∼ 2 with our ZFIRE survey12 where we have measured Hα fluxes for 90 star-forming galaxies selected from a mass-limited (log(Mz.astModot) > 9) sample based on ZFOURGE.13 The cluster galaxies (37) are part of a confirmed system at z=2.095 and the field galaxies (53) are at 1.9 < z < 2.4; all are in the COSMOS legacy field. There is no statistical difference between Hα- emitting cluster and field populations when comparing their star formation rate (SFR), stellar mass (M∗), galaxy size (reff ), SFR surface density (σ(H star)), and stellar age distributions. The only difference is that at fixed stellar mass, the Hα-emitting cluster galaxies are log(reff ) ∼ 0.1 larger than in the field. Approximately 19% of the Hα-emitters in the cluster and 26% in the field are IR-luminous (LIR > 2>× 1011 L⊙). Because the luminous IR galaxies in our combined sample are ∼5 times more massive than the low-IR galaxies, their radii are ∼70% larger. To track stellar growth, we separate galaxies into those that lie above, on, or below the Hα star-forming main sequence (SFMS) using δSFR(M∗)=±0.2 dex. Galaxies above the SFMS (starbursts) tend to have higher Hα SFR surface densities and younger light-weighted stellar ages than galaxies below the SFMS. Our results indicate that starbursts (+SFMS) in the cluster and field at z ∼ 2 are growing their stellar cores. Lastly, we compare to the (SFR-M∗) relation from RHAPSODY-G cluster simulations and find that the predicted slope is nominally consistent with the observations. However, the predicted cluster SFRs tend to be too low by a factor of ∼2, which seems to be a common problem for simulations across environment. |
Keywords | galaxies: evolution; galaxies: star formation; galaxies: starburst |
Funder | Directorate for Mathematical and Physical Sciences |
Byline Affiliations | Texas A&M University, United States |
Swinburne University of Technology | |
Leiden University, Netherlands | |
Australian National University | |
Macquarie University | |
Australian Astronomical Observatory, Australia | |
University of the Western Cape, South Africa | |
South African Astronomical Observatory, South Africa | |
African Institute for Mathematical Sciences, South Africa | |
University of California, United States |
https://research.usq.edu.au/item/w45x5/zfire-similar-stellar-growth-in-h-emitting-cluster-and-field-galaxies-at-z-2
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