A SUBSTANTIAL POPULATION OF MASSIVE QUIESCENT GALAXIES AT z ∼ 4 FROM ZFOURGE

• Published in: Astrophysical journal. Letters Vol. 783; no. 1; pp. 1 - 7
• Main Authors: Straatman, Caroline M S, Labbe, Ivo, Spitler, Lee R, Allen, Rebecca, Altieri, Bruno, Brammer, Gabriel B, Dickinson, Mark, van Dokkum, Pieter, Inami, Hanae, Glazebrook, Karl
• Format: Journal Article
• Language: English
• Published: United States 01.03.2014
• Subjects: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; Breaking; COLOR; COSMIC DUST; COSMOLOGY; DENSITY; DETECTION; ENERGY SPECTRA; FILTERS; GALACTIC EVOLUTION; GALAXIES; MASS; Photometry; Progenitors (astrophysics); RED SHIFT; Spectral energy distribution; Star formation; STARS; Stellar mass; Stellar populations; ULTRAVIOLET RADIATION
• ISSN: 2041-8205; 2041-8213
• DOI: 10.1088/2041-8205/783/1/L14

We report the likely identification of a substantial population of massive M ~ 10[sup 11] M galaxies at z ~ 4 with suppressed star formation rates (SFRs), selected on rest-frame optical to near-IR colors from the FourStar Galaxy Evolution Survey (ZFOURGE). The observed spectral energy distributions show pronounced breaks, sampled by a set of near-IR medium-bandwidth filters, resulting in tightly constrained photometric redshifts. Fitting stellar population models suggests large Balmer/4000A breaks, relatively old stellar populations, large stellar masses, and low SFRs, with a median specific SFR of 2.9 [+ or -]1.8 10[sup -11] yr[sup -1]. Ultradeep Herschel/PACS 100 mu m, 160 mu m and Spitzer/MIPS 24 mu m data reveal no dust-obscured SFR activity for 15/19(79%) galaxies. The study suggests that most of the star formation in the progenitors of quiescent z ~ 4 galaxies was obscured by dust.