A TURNOVER IN THE GALAXY MAIN SEQUENCE OF STAR FORMATION AT M* similar to 10(10)M(circle dot) FOR REDSHIFTS z < 1.3

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

来源：Astrophysical Journal, 2015, 801(2): 80.

DOI：10.1088/0004-637X/801/2/80

• galaxies: evolution
• galaxies: high-redshift
• galaxies: star formation

The relationship between galaxy star formation rates (SFRs) and stellar masses (M*) is reexamined using a mass-selected sample of similar to 62,000 star-forming galaxies at z <= 1.3 in the COSMOS 2 deg2 field. Using new far-infrared photometry from Herschel-PACS and SPIRE and Spitzer-MIPS 24 mu m, along with derived infrared luminosities from the NRK method based on galaxies' locations in the restframe color-color diagram (NUV - r) versus (r - K), we are able to more accurately determine total SFRs for our complete sample. At all redshifts, the relationship between median SFR 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 similar to 10(10) M-circle dot 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 +/- 0.10). A broken power-law fit below and above the turnover mass gives relationships of SFR proportional to M*(0.88 +/- 0.06) below the turnover mass and SFR proportional to M*(0.27 +/- 0.04) above the turnover mass. Galaxies more massive than M* greater than or similar to 10(10)M(circle dot) have a much lower average 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.

• 出版日期2015-3-10
• 单位中国地震局