J/A+A/617/A53 Red-sequence early-type galaxies. II. (Andreon, 2018)
The cosmic epoch dependence of environmental effects on size evolution of
red-sequence early-type galaxies.
Andreon S.
<Astron. Astrophys. 617, A53 (2018)>
=2018A&A...617A..53A 2018A&A...617A..53A (SIMBAD/NED BibCode)
ADC_Keywords: Galaxy catalogs ; Stars, masses
Keywords: galaxies: elliptical and lenticular, cD - galaxies: evolution -
galaxies: clusters: general
Abstract:
This work aims to observationally investigate the history of size
growth of early-type galaxies and how the growth depends on cosmic
epoch and the mass of the halo in which they are embedded. We carried
out a photometric and structural analysis in the rest-frame V band of
a mass-selected (logM/M☉>10.7) sample of red-sequence early-type
galaxies with spectroscopic/grism redshift in the general field up to
z=2 to complement a previous work presenting an identical analysis but
in halos 100 times more massive and 1000 times denser. We
homogeneously derived sizes (effective radii) fully accounting for the
multi-component nature of galaxies and the common presence of isophote
twists and ellipticity gradients. By using these mass-selected
samples, composed of 170 red-sequence early-type galaxies in the
general field and 224 identically selected and analyzed in clusters,
we isolate the effect on galaxy sizes of the halo in which galaxies
are embedded and its dependence on epoch. We find that the log of the
galaxy size at a fixed stellar mass, log M/M☉=11, has increased
with epoch at a rate twice as fast in the field than in cluster in the
last 10Gyr (0.26±0.03 versus 0.13±0.02dex per unit redshift).
Red-sequence early-type galaxies in the general field reached the size
of their cousins in denser environment by z=0.25±0.13 in spite of
being three times smaller at z∼2. Data point toward a model where size
growth is epoch-independent (i.e., ∂logre/∂z=c), but
with a rate c depending on environment,
∂c/∂logMhalo~=0.05. Environment determines the
growth rate (dlogre/dz) at all redshifts, indicating an external
origin for the galaxy growth without any clear epoch where it ceases
to have an effect. The larger size of early-type galaxies in massive
halos at high redshift indicates that their size grew buildup earlier
(at z>2) at an accelerated rate, slowing down at some still
unidentified z>2 redshift. Instead, the size growth rate of
red-sequence early-type galaxies in low-mass halos is reversed: it
proceeds at an increased rate at late epochs after an early period
(z>2) of reduced growth, in agreement with the qualitative
hierarchical picture of galaxy evolution. We found similar values of
scatter around the mass-size relation independently of environment and
epoch, indicating that the amount of dissipation in the system forming
the observed galaxy does not vary greatly with epoch or environment.
Description:
The table lists ID, coordinates, stellar mass, size (half-light radius
in the R band rest-frame) of a mass-selected (logM≳10.7) sample of 170
early-type galaxies on the red-sequence in the general field at
0.0<z<2.0. Sizes are derived fully accounting for the multi-component
nature of galaxies and the common presence of isophote twists and
ellipticity gradients. We also list applied (PSF) corrections to size.
A companion sample, based on identically selected cluster galaxies, is
at Cat. J/A+A/593/A2
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 59 169 *Coordinates, masses, sizes, and PSF corrections
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Note on table1.dat: More digits than needed are reported for all quantities.
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See also:
J/A+A/593/A2 : Red-sequence early-type galaxies in clusters (Andreon+, 2016)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Sample Sample (redshift or distance interval)
14- 21 A8 --- ID Galaxy designation (number or NGCNNNN)
23- 31 F9.5 deg RAdeg Right ascension (J2000)
33- 41 F9.5 deg DEdeg Declination (J2000)
43- 47 F5.2 [Msun] logM log10 of the stellar mass
49- 53 F5.2 [kpc] logre log10 of the half-light radius
(H0=70, {OMEGA}m=0.3 {OMAGA}λ=0.7)
55- 59 F5.2 [-] PSFcorr Applied correction to logre (in dex units)
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Acknowledgements:
Stefano Andreon, stefano.andreon(at)brera.inaf.it
References:
Andreon et al., Paper I 2016A&A...593A...2A 2016A&A...593A...2A, Cat. J/A+A/593/A2
(End) Patricia Vannier [CDS] 13-Jun-2018