AN HST/WFC3-IR MORPHOLOGICAL SURVEY OF GALAXIES AT z = 1.5-3.6. I. SURVEY DESCRIPTION AND MORPHOLOGICAL PROPERTIES OF STAR-FORMING GALAXIES

Journal Article · Fri Jan 20 04:00:00 EST 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/745/1/85· OSTI ID:22011942

Law, David R; Shapley, Alice E; Nagy, Sarah R ^[1]; Steidel, Charles C ^[2]; Reddy, Naveen A ^[3]

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1. Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States)
2. Department of Astronomy, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States)
3. National Optical Astronomy Observatories, 950 North Cherry Avenue, Tucson, AZ 85719 (United States)

We present the results of a 42-orbit Hubble Space Telescope Wide-Field Camera 3 (HST/WFC3) survey of the rest-frame optical morphologies of star-forming galaxies with spectroscopic redshifts in the range z = 1.5-3.6. The survey consists of 42 orbits of F160W imaging covering {approx}65 arcmin{sup 2} distributed widely across the sky and reaching a depth of 27.9 AB for a 5{sigma} detection within a 0.2 arcsec radius aperture. Focusing on an optically selected sample of 306 star-forming galaxies with stellar masses in the range M{sub *} = 10{sup 9}-10{sup 11} M{sub Sun }, we find that typical circularized effective half-light radii range from {approx}0.7 to 3.0 kpc and describe a stellar mass-radius relation as early as z {approx} 3. While these galaxies are best described by an exponential surface brightness profile (Sersic index n {approx} 1), their distribution of axis ratios is strongly inconsistent with a population of inclined exponential disks and is better reproduced by triaxial stellar systems with minor/major and intermediate/major axis ratios {approx}0.3 and 0.7, respectively. While rest-UV and rest-optical morphologies are generally similar for a subset of galaxies with HST/Advanced Camera for Surveys imaging data, differences are more pronounced at higher masses M{sub *} > 3 Multiplication-Sign 10{sup 10} M{sub Sun }. Finally, we discuss galaxy morphology in the context of efforts to constrain the merger fraction, finding that morphologically identified mergers/non-mergers generally have insignificant differences in terms of physical observables such as stellar mass and star formation rate, although merger-like galaxies selected according to some criteria have statistically smaller effective radii and correspondingly larger {Sigma}{sub SFR}.

• OSTI ID: 22011942
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 745; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BRIGHTNESS
GALAXIES
MASS
ORBITS
RED SHIFT
STARS
TELESCOPES