2011/06/08 by Daniel Szomoru, Marijn Franx, Rychard J. Bouwens +8 · 82 citations
Computer Science · Engineering · Physics and Astronomy · #Advanced Camera for Surveys #Advanced Image Processing Techniques #Astronomy #Astrophysics #Brightest cluster galaxy #CCD and CMOS Imaging Sensors #Elliptical galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Hubble Deep Field #Hubble Ultra-Deep Field #Hubble space telescope #Lenticular galaxy #Luminous infrared galaxy #Physics #Redshift #Star formation #Stellar mass #Wide Field Camera 3 #astro-ph.CO
paper · pdf · doi:10.1088/2041-8205/735/1/l22
published in The Astrophysical Journal Letters 735(1), L22 (IOP Publishing) · Accepted for publication in ApJ Letters, 7 pages, 4 figures
arxiv created 2011/06/08 · openalex publication_date 2011/06/10 · arxiv updated 2011/06/15 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
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 ∼ 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 ∼ 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 ∼ 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: (Δ( u − g rest )/Δ(log r )) median = −0.47, −0.33, and −0.46 for z ∼ 2, z ∼ 1, and z = 0, respectively. Using structural parameters derived from surface brightness profiles we confirm that at z ∼ 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 Sérsic 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.