Environmental Effects on the Star Formation Activity in Galaxies at z=1.2 in the COSMOS Field

Abstract

We investigate the relation between the star-formation activity in galaxies and environment at z=1.2 in the COSMOS field, using the fraction of [OII] emitters and the local galaxy density. The fraction of [OII] emitters appears to be almost constant over the surface density of galaxies between 0.2 and 10 Mpc^-2. This trend is different from that seen in the local universe where the star-formation activity is weaker in higher density regions. To understand this difference between z~1 and z~0, we study the fraction of non-isolated galaxies as a function of local galaxy density. We find that the fraction of non-isolated galaxies increases with increasing density. Our results suggest that the star formation in galaxies at z~1 is triggered by galaxy interaction and/or mergers.

10pages, 5figures, accepted for publication in ApJ

References in corpus (13)

• The Cosmic Evolution Survey (COSMOS) -- Overview
• COSMOS Photometric Redshifts with 30-bands for 2-deg2
• zCOSMOS: A Large VLT/VIMOS redshift survey covering 0 < z < 3 in the COSMOS field
• The Cosmic Evolution Survey (COSMOS): Subaru Observations of the HST COSMOS Field
• The DEEP2 Galaxy Redshift Survey: The Role of Galaxy Environment in the Cosmic Star-Formation History
• The Redshift Evolution of Wet, Dry, and Mixed Galaxy Mergers from Close Galaxy Pairs in the DEEP2 Galaxy Redshift Survey
• Large Structures and Galaxy Evolution in COSMOS at z < 1.1
• The effects of environment on morphological evolution between 0<z<1.2 in the COSMOS Survey
• Tidally Triggered Star Formation in Close Pairs of Galaxies: Major and Minor Interactions
• Lyman Alpha Emitters at Redshift 5.7 in the COSMOS Field
• Rapid Evolution in the Most Luminous Galaxies During the First 900 Million Years
• The H$\alpha$ Luminosity Function and Star Formation Rate at $z\approx 0.24$ in the Cosmos 2 Square-Degree Field
• The [OII]3727 Luminosity function and Star Formation Rate at z~1.2 in the COSMOS 2 Square-degree Field and the Subaru Deep Field

Cited by in corpus (3)

• The environmental impacts on the star formation main sequence: an H-alpha study of the newly discovered rich cluster at z=1.52
• VIS3COS: III. environmental effects on the star formation histories of galaxies at z~0.8 seen in [OII], H$\delta$, and Dn4000
• On the Reversal of SFR-Density Relation at z=1: Insights from Simulations