Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published January 21, 2016 | Submitted + Published
Journal Article Open

Non-linearity and environmental dependence of the star-forming galaxies main sequence

Abstract

Using data from four deep fields (COSMOS, AEGIS, ECDFS, and CDFN), we study the correlation between the position of galaxies in the star formation rate (SFR) versus stellar mass plane and local environment at z < 1.1. To accurately estimate the galaxy SFR, we use the deepest available Spitzer/MIPS 24 and Herschel/PACS data sets. We distinguish group environments (M_(halo) ∼ 10^(12.5–14.2) M_⊙) based on the available deep X-ray data and lower halo mass environments based on the local galaxy density. We confirm that the main sequence (MS) of star-forming galaxies is not a linear relation and there is a flattening towards higher stellar masses (M_* > 10^(10.4–10.6) M_⊙), across all environments. At high redshift (0.5 < z < 1.1), the MS varies little with environment. At low redshift (0.15 < z < 0.5), group galaxies tend to deviate from the mean MS towards the region of quiescence with respect to isolated galaxies and less-dense environments. We find that the flattening of the MS towards low SFR is due to an increased fraction of bulge-dominated galaxies at high masses. Instead, the deviation of group galaxies from the MS at low redshift is caused by a large fraction of red disc-dominated galaxies which are not present in the lower density environments. Our results suggest that above a mass threshold (∼10^(10.4–10^(10.6 )M_⊙) stellar mass, morphology and environment act together in driving the evolution of the star formation activity towards lower level. The presence of a dominating bulge and the associated quenching processes are already in place beyond z ∼1. The environmental effects appear, instead, at lower redshifts and have a long time-scale.

Additional Information

© 2015 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. Accepted 2015 October 23. Received 2015 October 16. In original form 2015 June 25. First published online November 25, 2015. The authors acknowledge Alvio Renzini and Michael L. Balogh for their useful comments and discussion on the early draft. PACS has been developed by a consortium of institutes led by MPE (Germany) and including UVIE (Austria); KUL, CSL, IMEC (Belgium); CEA, OAMP (France); MPIA (Germany); IFSI, OAP/AOT, OAA/CAISMI, LENS, SISSA (Italy); IAC (Spain). This development has been supported by the funding agencies BMVIT (Austria), ESA-PRODEX (Belgium), CEA/CNES (France), DLR (Germany), ASI (Italy) and CICYT/MCYT (Spain). This research has made use of NASA's Astrophysics Data System, of NED, which is operated by JPL/Caltech, under contract with NASA, and of SDSS, which has been funded by the Sloan Foundation, NSF, the US Department of Energy, NASA, the Japanese Monbukagakusho, the Max Planck Society, and the Higher Education Funding Council of England. The SDSS is managed by the participating institutions (www.sdss.org/collaboration/credits.html). We gratefully acknowledge the contributions of the entire COSMOS collaboration consisting of more than 100 scientists. More information about the COSMOS survey is available at http://www.astro.caltech.edu/cosmos. This project has been supported by the DLR grant 50OR1013 to MPE.

Attached Files

Published - MNRAS-2016-Erfanianfar-2839-51.pdf

Submitted - 1511.01899v1.pdf

Files

MNRAS-2016-Erfanianfar-2839-51.pdf
Files (7.5 MB)
Name Size Download all
md5:bd852ed20007ffc3f14f630cfe2c2c18
5.2 MB Preview Download
md5:5b53bbb221436df81cb3a891953143fc
2.3 MB Preview Download

Additional details

Created:
August 20, 2023
Modified:
October 17, 2023