1 research outputs found
ZFIRE: Similar Stellar Growth in Hα-emitting Cluster and Field Galaxies at z ~ 2
We compare galaxy scaling relations as a function of environment at
with our ZFIRE survey where we have measured H fluxes for 90
star-forming galaxies selected from a mass-limited
[] sample based on ZFOURGE. The cluster galaxies
(37) are part of a confirmed system at z=2.095 and the field galaxies (53) are
at ; all are in the COSMOS legacy field. There is no statistical
difference between H-emitting cluster and field populations when
comparing their star formation rate (SFR), stellar mass (), galaxy
size (), SFR surface density [(H)], and stellar
age distributions. The only difference is that at fixed stellar mass, the
H-emitting cluster galaxies are larger than in
the field. Approximately 19% of the H-emitters in the cluster and 26%
in the field are IR-luminous (). Because the
LIRGs in our combined sample are times more massive than the low-IR
galaxies, their radii are % larger. To track stellar growth, we
separate galaxies into those that lie above, on, and below the H
star-forming main sequence (SFMS) using SFR dex.
Galaxies above the SFMS (starbursts) tend to have higher H SFR surface
densities and younger light-weighted stellar ages compared to galaxies below
the SFMS. Our results indicate that starbursts (+SFMS) in the cluster and field
at are growing their stellar cores. Lastly, we compare to the
(SFR-) relation from RHAPSODY cluster simulations and find the
predicted slope is nominally consistent with the observations. However, the
predicted cluster SFRs tend to be too low by a factor of which seems to
be a common problem for simulations across environment.Comment: ApJ in press; full version of Table 1 available from ApJ and upon
request. Survey websites are http://zfire.swinburne.edu.au and
http://zfourge.tamu.ed