A Turnover in the Galaxy Main Sequence of Star Formation at $M_{*} \sim 10^{10} M_{\odot}$ for Redshifts $z < 1.3$

Nicholas Lee; D. B. Sanders; Caitlin M. Casey; Sune Toft; N. Z. Scoville; Chao-Ling Hung; Emeric Le Floc'h; Olivier Ilbert; H. Jabran Zahid; Herve Aussel; Peter Capak; Jeyhan S. Kartaltepe; Lisa J. Kewley; Yanxia Li; Kevin Schawinski; Kartik Sheth; Quanbao Xiao

doi:10.1088/0004-637X/801/2/80

paper

A Turnover in the Galaxy Main Sequence of Star Formation at $M_{*} \sim 1 0^{10} M_{⊙}$ for Redshifts $z < 1.3$

arXiv:1501.01080 · doi:10.1088/0004-637X/801/2/80

Abstract

The relationship between galaxy star formation rates (SFR) and stellar masses ( $M_{*}$ ) is re-examined using a mass-selected sample of $\sim$ 62,000 star-forming galaxies at $z \leq 1.3$ in the COSMOS 2-deg $^{2}$ field. Using new far-infrared photometry from $H er sc h e l$ -PACS and SPIRE and $S p i t z er$ -MIPS 24 $μ$ m, along with derived infrared luminosities from the NRK method based on galaxies' locations in the restframe color-color diagram $(N U V - r)$ vs. $(r - K)$ , we are able to more accurately determine total SFRs for our complete sample. At all redshifts, the relationship between median $S F R$ and $M_{*}$ follows a power-law at low stellar masses, and flattens to nearly constant SFR at high stellar masses. We describe a new parameterization that provides the best fit to the main sequence and characterizes the low mass power-law slope, turnover mass, and overall scaling. The turnover in the main sequence occurs at a characteristic mass of about $M_{0} \sim 1 0^{10} M_{⊙}$ at all redshifts. The low mass power-law slope ranges from 0.9-1.3 and the overall scaling rises in SFR as a function of $(1 + z)^{4.12 \pm 0.10}$ . A broken power-law fit below and above the turnover mass gives relationships of $S F R \propto M_{*}^{0.88 \pm 0.06}$ below the turnover mass and $S F R \propto M_{*}^{0.27 \pm 0.04}$ above the turnover mass. Galaxies more massive than $M_{*} ≳ 1 0^{10} M_{⊙}$ have on average, a much lower specific star formation rate (sSFR) than would be expected by simply extrapolating the traditional linear fit to the main sequence found for less massive galaxies.

16 pages, 7 figures. Accepted for publication in ApJ

A Turnover in the Galaxy Main Sequence of Star Formation at $M_{*} \sim 1 0^{10} M_{⊙}$ for Redshifts $z < 1.3$

Abstract

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A Turnover in the Galaxy Main Sequence of Star Formation at M∗​∼1010M⊙​ for Redshifts z<1.3

Abstract

References in corpus (22)

Cited by in corpus (118)

A Turnover in the Galaxy Main Sequence of Star Formation at $M_{*} \sim 1 0^{10} M_{⊙}$ for Redshifts $z < 1.3$