Evolution of the Frequency of Luminous (\geq L_V*) Close Galaxy Pairs at z < 1.2 in the COSMOS Field
arXiv:0705.2266 · doi:10.1086/519953
Abstract
We measure the fraction of luminous galaxies in pairs at projected separations of 5-20 kpc out to z=1.2 in the COSMOS field using ACS images and photometric redshifts derived from an extensive multiwavelength dataset. Analysis of a complete sample of 106,188 galaxies more luminous than M_V=-19.8 (~ L_V*) in the redshift range 0.1 < z < 1.2 yields 1,749 galaxy pairs. These data are supplemented by a local z=0-0.1 value for the galaxy pair fraction derived from the Sloan Digital Sky Survey (SDSS). After statistically correcting the COSMOS pair sample for chance line-of-sight superpositions, the evolution in the pair fraction is fit by a power law \propto (1+z)^{n=3.1 \pm 0.1}. If this strongly evolving pair fraction continues out to higher redshift, ~ 50% of all luminous galaxies at z ~ 2 are in close pairs. This clearly signifies that galaxy mergers are a very significant and possibly dominant mechanism for galaxy evolution during the epoch of galaxy formation at z=1 to 3.
arXiv comment22 pages including 4 figures and 2 tables. Accepted for publication in the ApJS COSMOS special issue. For the high resolution version of figure 4, see: http://www.ifa.hawaii.edu/~jeyhan/pairs/
References in corpus (21)
- The Cosmic Evolution Survey (COSMOS) -- Overview
- The COSMOS Survey: Hubble Space Telescope / Advanced Camera for Surveys (HST/ACS) Observations and Data Processing
- The Luminosity Function of Galaxies in SDSS Commissioning Data
- The Spitzer Legacy Survey of the HST-ACS 2 sq. deg. COSMOS Field: survey strategy and first analysis
- A Direct Measurement of Major Galaxy Mergers at z < 3
- COSMOS : Hubble Space Telescope Observations
- Towards an understanding of the rapid decline of the cosmic star formation rate
- Weak Gravitational Lensing with COSMOS: Galaxy Selection and Shape Measurements
- The Cosmic Evolution Survey (COSMOS): Subaru Observations of the HST COSMOS Field
- The Deep2 Galaxy Redshift Survey: Evolution of Close Galaxy Pairs and Major-Merger Rates Up to z ~ 1.2
- Large Structures and Galaxy Evolution in COSMOS at z < 1.1
- Dynamical properties of Ultraluminous Infrared Galaxies I: Mass ratio conditions for ULIRG activity in interacting pairs
- Photometric Redshifts of Galaxies in COSMOS
- Close Pairs of Field Galaxies in the CNOC1 Redshift Survey
- A Survey of Faint Galaxy Pairs
- Hubble Space Telescope H-Band Imaging Survey of Massive Gas-Rich Mergers
- Near Infrared Adaptive Optics Imaging of QSO Host Galaxies
- The Merger Rate to Redshift One from Kinematic Pairs: Caltech Faint Galaxy Redshift Survey XI
- Probing the Evolution of the Galaxy Interaction/Merger Rate Using Collisional Ring Galaxies
- Counting Pairs of Faint Galaxies
- Merging Galaxies in the SDSS EDR