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. =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 0.25deg^2^ to study the structural evolution of massive early-type galaxies since z~2. Mass-selected samples, complete down to log(M/M_{sun}_)~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 0.61 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_{sun}_)>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_{sun}_)~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). File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 32 394 Massive early-type galaxies: 0.610.7 and sSFR<1/3t_H_(z) -------------------------------------------------------------------------------- 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