J/ApJ/762/83 Massive early-type galaxies in K-band (Chang+, 2013)
Shape evolution of massive early-type galaxies: confirmation of increased disk
prevalence at z>1.
Chang Y.-Y., van der Wel A., Rix H.-W., Wuyts S., Zibetti S., Ramkumar B.,
Holden B.
<Astrophys. J., 762, 83 (2013)>
=2013ApJ...762...83C 2013ApJ...762...83C
ADC_Keywords: Galaxies, IR ; Redshifts ; Stars, masses
Keywords: cosmology: observations; galaxies: elliptical and lenticular, cD;
galaxies: evolution; galaxies: formation; galaxies: structure
Abstract:
We use high-resolution K-band VLT/HAWK-I imaging over 0.25deg2 to
study the structural evolution of massive early-type galaxies since
z∼2. Mass-selected samples, complete down to log(M/M☉)∼10.7 such
that "typical" (L*) galaxies are included at all redshifts, are drawn
from pre-existing photometric redshift surveys. We then separate the
samples into different redshift slices and classify them as late- or
early-type galaxies on the basis of their specific star formation
rate. Axis-ratio measurements for the ∼400 early-type galaxies in the
redshift range 0.6<z<1.8 are accurate to 0.1 or better. The projected
axis-ratio distributions are then compared with lower redshift
samples. We find strong evidence for evolution of the population
properties: early-type galaxies at z>1 are, on average, flatter than
at z<1 and the median projected axis ratio at a fixed mass decreases
with redshift. However, we also find that at all epochs z≲2, the most
massive early-type galaxies (log(M/M☉)>11.3) are the roundest,
with a pronounced lack of galaxies that are flat in projection.
Merging is a plausible mechanism that can explain both results: at all
epochs, merging is required for early-type galaxies to grow beyond
log(M/M☉)∼11.3, and all early types over time gradually and
partially lose their disk-like characteristics.
Description:
High-resolution K-band imaging from VLT/HAWK-I is central to our study
to provide the structural parameters. We have obtained 1hr exposures
for each of 16 adjacent tiles in a 30'x30' mosaic that covers the full
ECDFS (Taylor et al. 2009, Cat. J/ApJS/183/295;
ESO program ID: 082.A-0890), which is coincident with the HST/ACS
coverage from GEMS (Galaxy Evolution from Morphologies and SEDs; Rix
et al. 2004ApJS..152..163R 2004ApJS..152..163R).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 32 394 Massive early-type galaxies: 0.6<z<1.8,
log(M/MSun)>10.7 and sSFR<1/3tH(z)
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See also:
J/A+A/557/A66 : IR galaxies effective SEDs at various z (Bethermin+, 2013)
J/MNRAS/428/1460 : Massive early-type galaxies (Buitrago+, 2013)
J/MNRAS/427/1666 : Massive galaxies in CANDELS-UDS field (Bruce+, 2012)
J/ApJS/203/24 : Structural param. of CANDELS galaxies (van der Wel+, 2012)
J/ApJ/742/3 : Photometric catalogs for ECDF-S and CDF-N (Rafferty+, 2011)
J/ApJ/735/L22 : HUDF galaxy properties at z∼2 (Szomoru+, 2011)
J/MNRAS/414/888 : ATLAS3D project. III. (Emsellem+, 2011)
J/MNRAS/412/727 : SDSS red gal. automated morph. classification (Cheng+, 2011)
J/ApJS/191/124 : Opt. spectroscopy of ECDF-S X-ray sources (Silverman+, 2010)
J/ApJS/189/270 : MUSYC optical imaging in ECDF-S (Cardamone+, 2010)
J/ApJ/693/617 : Ellipticities of cluster early-type galaxies (Holden+, 2009)
J/ApJS/183/295 : A K-selected catalog of the ECDFS from MUSYC (Taylor+, 2009)
J/ApJS/174/136 : GEMS survey data and catalog (Caldwell+, 2008)
J/ApJS/172/615 : GALFIT result for GEMS galaxies (Haussler+, 2007)
J/ApJ/655/51 : HDFS IRAC observations of 2<z<3.5 galaxies (Wuyts+, 2007)
J/AJ/134/1103 : MUSYC deep near-infrared imaging (Quadri+, 2007)
J/ApJS/162/1 : MUSYC: optical source catalog (Gawiser+, 2006)
J/ApJ/642/L13 : ECDFS MUSYC gal. UBVRIzNB5000 photometry (Gawiser+, 2006)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- [CVU2010] [4032/78536] ID; same as Cardamone et al.
2010, Cat. J/ApJS/189/270
7- 10 F4.2 --- z [0.6/1.8] Photometric redshift from EAzY
(Brammer et al. 2008ApJ...686.1503B 2008ApJ...686.1503B)
12- 16 F5.2 [Msun] logM* [10.7/12] Log of the stellar mass from FAST
(Kriek et al. 2009ApJ...700..221K 2009ApJ...700..221K)
18- 22 F5.2 mag Kmag [17.6/22] K-band magnitude from GALFIT
24- 27 F4.2 arcsec Rad [0/3] Effective radius from GALFIT
29- 32 F4.2 --- qproj [0.1/1] Projected axis ratio from GALFIT
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 02-Sep-2014