TY - JOUR
T1 - The sizes of massive quiescent and star-forming galaxies at z ∼ 4 with ZFOURGE and CANDELS
AU - Straatman, Caroline M S
AU - Labbé, Ivo
AU - Spitler, Lee R.
AU - Glazebrook, Karl
AU - Tomczak, Adam
AU - Allen, Rebecca
AU - Brammer, Gabriel B.
AU - Cowley, Michael
AU - Dokkum, Pieter Van
AU - Kacprzak, Glenn G.
AU - Kawinwanichakij, Lalit
AU - Mehrtens, Nicola
AU - Nanayakkara, Themiya
AU - Papovich, Casey
AU - Persson, S. Eric
AU - Quadri, Ryan F.
AU - Rees, Glen
AU - Tilvi, Vithal
AU - Tran, Kim Vy H
AU - Whitaker, Katherine E.
N1 - Copyright 2015 The American Astronomical Society. Firstly published in the Astrophysical Journal Letters, 808(1), L29, 2015, published by IOP Publishing. The original publication is available at http://www.doi.org/10.1088/2041-8205/808/1/L29. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.
PY - 2015/7/20
Y1 - 2015/7/20
N2 - We study the rest-frame ultraviolet (UV) sizes of massive (∼0.8 × 1011M⊙) galaxies at 3.4 蠐 z < 4.2, selected from the FourStar Galaxy Evolution Survey, by fitting single Sersic profiles to Hubble Space Telescope/WFC3/ F160W images from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey. Massive quiescent galaxies are very compact, with a median circularized half-light radius re = 0.63 ± 0.18 kpc. Removing 5/16 (31%) sources with signs of active galactic nucleus activity does not change the result. Star-forming galaxies have re = 2.0 ± 0.60 kpc, 3.2 ± 1.3×larger than quiescent galaxies. Quiescent galaxies at z ∼ 4 are on average 6.0 ± 1.7×smaller than at z ∼ 0 and 1.9 ± 0.7×smaller than at z ∼ 2. Star-forming galaxies of the same stellar mass are 2.4 ± 0.7×smaller than at z ∼ 0. Overall, the size evolution at 0 < z < 4 is well described by a power law, with re 5.08 0.28(1 z) = ± + -1.44 ±0.08 kpc for quiescent galaxies and r 6.02 0.28(1 z) e = ± + -0.72 ±0.05 kpc for star-forming galaxies. Compact star-forming galaxies are rare in our sample: we find only1 14 (7%) with re (M 10 M ) 1.5 11 0.75 < ⊙ , whereas 13 16 (81%) of the quiescent galaxies are compact. The number density of compact quiescent galaxies at z ∼ 4 is 1.8 ± 0.8 × 10-5 Mpc-3 and increases rapidly, by >5×, between 2 < z < 4. The paucity of compact star-forming galaxies at z ∼ 4 and their large rest-frame UV median sizes suggest that the formation phase of compact cores is very short and/or highly dust obscured.
AB - We study the rest-frame ultraviolet (UV) sizes of massive (∼0.8 × 1011M⊙) galaxies at 3.4 蠐 z < 4.2, selected from the FourStar Galaxy Evolution Survey, by fitting single Sersic profiles to Hubble Space Telescope/WFC3/ F160W images from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey. Massive quiescent galaxies are very compact, with a median circularized half-light radius re = 0.63 ± 0.18 kpc. Removing 5/16 (31%) sources with signs of active galactic nucleus activity does not change the result. Star-forming galaxies have re = 2.0 ± 0.60 kpc, 3.2 ± 1.3×larger than quiescent galaxies. Quiescent galaxies at z ∼ 4 are on average 6.0 ± 1.7×smaller than at z ∼ 0 and 1.9 ± 0.7×smaller than at z ∼ 2. Star-forming galaxies of the same stellar mass are 2.4 ± 0.7×smaller than at z ∼ 0. Overall, the size evolution at 0 < z < 4 is well described by a power law, with re 5.08 0.28(1 z) = ± + -1.44 ±0.08 kpc for quiescent galaxies and r 6.02 0.28(1 z) e = ± + -0.72 ±0.05 kpc for star-forming galaxies. Compact star-forming galaxies are rare in our sample: we find only1 14 (7%) with re (M 10 M ) 1.5 11 0.75 < ⊙ , whereas 13 16 (81%) of the quiescent galaxies are compact. The number density of compact quiescent galaxies at z ∼ 4 is 1.8 ± 0.8 × 10-5 Mpc-3 and increases rapidly, by >5×, between 2 < z < 4. The paucity of compact star-forming galaxies at z ∼ 4 and their large rest-frame UV median sizes suggest that the formation phase of compact cores is very short and/or highly dust obscured.
UR - http://www.scopus.com/inward/record.url?scp=84937791988&partnerID=8YFLogxK
U2 - 10.1088/2041-8205/808/1/L29
DO - 10.1088/2041-8205/808/1/L29
M3 - Article
VL - 808
SP - 1
EP - 8
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
SN - 2041-8205
IS - 1
M1 - L29
ER -