AEGIS: The Diversity of Bright Near-IR Selected Distant RedGalaxies

Journal Article · Fri Oct 13 04:00:00 EDT 2006 · Astrophysical Journal Letters

OSTI ID:919264

Conselice, C J; Newman, J A; Georgakakis, A; Almaini, O; Coil, A L; Cooper, M C; Eisenhardt, P; Foucaud, S; Koekemoer, A; Lotz, J; Noeske, K; Weiner, B; Willmer, C N A

We use deep and wide near infrared (NIR) imaging from the Palomar telescope combined with DEEP2 spectroscopy and Hubble Space Telescope (HST) and Chandra Space Telescope imaging to investigate the nature of galaxies that are red in NIR colors. We locate these 'distant red galaxies' (DRGs) through the color cut (J - K){sub vega} > 2.3 over 0.7 deg{sup 2}, where we find 1010 DRG candidates down to K{sub s} = 20.5. We combine 95 high quality spectroscopic redshifts with photometric redshifts from BRIJK photometry to determine the redshift and stellar mass distributions for these systems, and morphological/structural and X-ray properties for 107 DRGs in the Extended Groth Strip. We find that many bright (J - K){sub vega} > 2.3 galaxies with K{sub s} < 20.5 are at redshifts z < 2, with 64% between 1 < z < 2. The stellar mass distributions for these galaxies is broad, ranging from 10{sup 9} - 10{sup 12} M{sub {circle_dot}} , but with most z > 2 systems massive with M{sub *} > 10{sup 11} M{sub {circle_dot}}. HST imaging shows that the structural properties and morphologies of DRGs are also diverse, with the majority elliptical/compact (57%), and the remainder edge-on spirals (7%), and peculiar galaxies (29%). The DRGs at z < 1.4 with high quality spectroscopic redshifts are generally compact, with small half-light radii, and span a range in rest-frame optical properties. The spectral energy distributions for these objects differ from higher redshift DRGs: they are bluer by one magnitude in observed (I - J) color. A pure IR color selection of high redshift populations is not sufficient to identify unique populations, and other colors, or spectroscopic redshifts are needed to produce homogeneous samples.

• Research Organization: Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
• Sponsoring Organization: USDOE Director, Office of Science; National Aeronautics andSpace Administration
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 919264
• Report Number(s): LBNL--61754; BnR: 400409900
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 1 Vol. 660
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COLOR
ENERGY SPECTRA
GALAXIES
Galaxies
MASS DISTRIBUTION
OPTICAL PROPERTIES
PHOTOMETRY
SPECTROSCOPY
TELESCOPES