EARLY-TYPE GALAXIES AT z ∼ 1.3. IV SCALING RELATIONS IN DIFFERENT ENVIRONMENTS

• Published in: The Astrophysical journal Vol. 745; no. 2; pp. 1 - 17
• Main Authors: RAICHOOR, A, MEI, S, ILLINGWORTH, G, KODAMA, T, POSTMAN, M, RETTURA, A, BLAKESLEE, J. P, DEMARCO, R, JEE, M. J, WHITE, R. L, STANFORD, S. A, HOLDEN, B. P, NAKATA, F, ROSATI, P, SHANKAR, F, TANAKA, M, FORD, H, HUERTAS-COMPANY, M
• Format: Journal Article
• Language: English
• Published: Bristol IOP 01-02-2012; American Astronomical Society
• Subjects: Astronomy; Astrophysics; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CAMERAS; Clusters; Earth, ocean, space; Exact sciences and technology; GALACTIC EVOLUTION; GALAXIES; GALAXY CLUSTERS; Hubble Space Telescope; MASS; PHOTOMETRY; Physics; Progenitors (astrophysics); RED SHIFT; Spreads; TELESCOPES; Trends; UNIVERSE; WAVELENGTHS; Galaxy evolution; Superclusters; Red shift; galaxies: clusters: individual (RX J0849+4452, RX J0848+4453); Elliptical galaxies; galaxies: evolution; galaxies: fundamental parameters; galaxies: high-redshift; Galaxy clusters; galaxies: elliptical and lenticular, cD; galaxies: formation; Galaxy formation; Early type galaxies; Photometry
• ISSN: 0004-637X; 1538-4357
• DOI: 10.1088/0004-637X/745/2/130

We present the Kormendy and mass-size relations (MSR) for early-type galaxies (ETGs) as a function of environment at z ~ 1.3. Our sample includes 76 visually classified ETGs with masses 10 super(10) < M/M sub([middot in circle]) < 10 super(11.5), selected in the Lynx supercluster and in the Great Observatories Origins Deep Survey/Chandra Deep Field South field; 31 ETGs in clusters, 18 in groups, and 27 in the field, all with multi-wavelength photometry and Hubble Space Telescope/Advanced Camera for Surveys observations. The Kormendy relation, in place at z ~ 1.3, does not depend on the environment. The MSR reveals that ETGs overall appear to be more compact in denser environments: cluster ETGs have sizes on average around 30%-50% smaller than those of the local universe and a distribution with a smaller scatter, whereas field ETGs show an MSR with a similar distribution to the local one. Our results imply that (1) the MSR in the field did not evolve overall from z ~ 1.3 to present; this is interesting and in contrast to the trend found at higher masses from previous works; (2) in denser environments, either ETGs have increased in size by 30%-50% on average and spread their distributions, or more ETGs have been formed within the dense environment from non-ETG progenitors, or larger galaxies have been accreted to a pristine compact population to reproduce the MSR observed in the local universe. Our results are driven by galaxies with masses M [<, ~] 2 x 10 super(11) M sub([middot in circle]) and those with masses M ~ 10 super(11) M sub([middot in circle]) follow the same trends as that of the entire sample. Following the Valentinuzzi et al. definition of superdense ETGs, ~35%-45% of our cluster sample is made up of superdense ETGs.