MORPHOLOGICAL EVOLUTION OF GALAXIES FROM ULTRA-DEEP HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3 IMAGING: THE HUBBLE SEQUENCE AT z {approx} 2

Journal Article · Fri Jul 01 04:00:00 EDT 2011 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/735/1/L22· OSTI ID:21562567

Szomoru, Daniel; Franx, Marijn; Bouwens, Rychard J; Labbe, Ivo ^[1]; Van Dokkum, Pieter G ^[2]; Illingworth, Garth D ^[3]; Trenti, Michele ^[4]

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1. Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands)
2. Department of Astronomy, Yale University, New Haven, CT 06520-8101 (United States)
3. UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States)
4. Center for Astrophysics and Space Astronomy, University of Colorado, 389-UCB, Boulder, CO 80309 (United States)

We use ultra-deep Hubble Space Telescope Wide Field Camera 3/infrared imaging of the Hubble Ultra Deep Field to investigate the rest-frame optical morphologies of a mass-selected sample of galaxies at z {approx} 2. We find a large variety of galaxy morphologies, ranging from large, blue, disk-like galaxies to compact, red, early-type galaxies. We derive rest-frame u - g color profiles for these galaxies and show that most z {approx} 2 galaxies in our sample have negative color gradients such that their cores are red. Although these color gradients may partly be caused by radial variations in dust content, they point to the existence of older stellar populations in the centers of z {approx} 2 galaxies. This result is consistent with an 'inside-out' scenario of galaxy growth. We find that the median color gradient is fairly constant with redshift: ({Delta}(u - g{sub rest})/{Delta}(log r)){sub median} = -0.47, -0.33, and -0.46 for z {approx} 2, z {approx} 1, and z = 0, respectively. Using structural parameters derived from surface brightness profiles we confirm that at z {approx} 2 galaxy morphology correlates well with specific star formation rate. At the same mass, star-forming galaxies have larger effective radii, bluer rest-frame u - g colors, and lower Sersic indices than quiescent galaxies. These correlations are very similar to those at lower redshift, suggesting that the relations that give rise to the Hubble sequence at z = 0 are already in place for massive galaxies at this early epoch.

• OSTI ID: 21562567
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 1 Vol. 735; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BRIGHTNESS
COLOR
CORRELATIONS
COSMOLOGY
EVOLUTION
GALACTIC EVOLUTION
GALAXIES
MASS
MORPHOLOGY
OPTICAL PROPERTIES
ORGANOLEPTIC PROPERTIES
PHYSICAL PROPERTIES
RED SHIFT