HST/WFC3 CONFIRMATION OF THE INSIDE-OUT GROWTH OF MASSIVE GALAXIES AT 0 < z < 2 AND IDENTIFICATION OF THEIR STAR-FORMING PROGENITORS AT z {approx} 3

Journal Article · Wed Mar 20 04:00:00 EDT 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/766/1/15· OSTI ID:22167587

Patel, Shannon G.; Franx, Marijn; Muzzin, Adam ^[1]; Van Dokkum, Pieter G. ^[2]; Quadri, Ryan F.; Williams, Rik J. ^[3]; Marchesini, Danilo ^[4]; Holden, Bradford P. ^[5]; Stefanon, Mauro ^[6]

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1. Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 AA Leiden (Netherlands)
2. Department of Astronomy, Yale University, New Haven, CT 06520-8101 (United States)
3. Observatories of the Carnegie Institution of Washington, Pasadena, CA 91101 (United States)
4. Department of Physics and Astronomy, Tufts University, Medford, MA 02155 (United States)
5. UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States)
6. Observatori Astronomic de la Universitat de Valencia, E-46980 Paterna, Valencia (Spain)

We study the structural evolution of massive galaxies by linking progenitors and descendants at a constant cumulative number density of n{sub c} = 1.4 Multiplication-Sign 10{sup -4} Mpc{sup -3} to z {approx} 3. Structural parameters were measured by fitting Sersic profiles to high-resolution CANDELS HST WFC3 J{sub 125} and H{sub 160} imaging in the UKIDSS-UDS at 1 < z < 3 and ACS I{sub 814} imaging in COSMOS at 0.25 < z < 1. At a given redshift, we selected the HST band that most closely samples a common rest-frame wavelength so as to minimize systematics from color gradients in galaxies. At fixed n{sub c}, galaxies grow in stellar mass by a factor of {approx}3 from z {approx} 3 to z {approx} 0. The size evolution is complex: galaxies appear roughly constant in size from z {approx} 3 to z {approx} 2 and then grow rapidly to lower redshifts. The evolution in the surface mass density profiles indicates that most of the mass at r < 2 kpc was in place by z {approx} 2, and that most of the new mass growth occurred at larger radii. This inside-out mass growth is therefore responsible for the larger sizes and higher Sersic indices of the descendants toward low redshift. At z < 2, the effective radius evolves with the stellar mass as r{sub e} {proportional_to}M {sup 2.0}, consistent with scenarios that find dissipationless minor mergers to be a key driver of size evolution. The progenitors at z {approx} 3 were likely star-forming disks with r{sub e} {approx} 2 kpc, based on their low Sersic index of n {approx} 1, low median axis ratio of b/a {approx} 0.52, and typical location in the star-forming region of the U - V versus V - J diagram. By z {approx} 1.5, many of these star-forming disks disappeared, giving rise to compact quiescent galaxies. Toward lower redshifts, these galaxies continued to assemble mass at larger radii and became the local ellipticals that dominate the high-mass end of the mass function at the present epoch.

• OSTI ID: 22167587
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 766; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COLOR
DENSITY
DIAGRAMS
GALACTIC EVOLUTION
GALAXIES
GROWTH
MASS
RED SHIFT
RESOLUTION
STARS
WAVELENGTHS