Towards a robust estimate of the merger rate evolution using near-IR photometry

Rawat, Abhishek ; Hammer, Francois ; Kembhavi, Ajit K. ; Flores, Hector (2007) Towards a robust estimate of the merger rate evolution using near-IR photometry Proceedings of the International Astronomical Union, 3 . pp. 469-470. ISSN 1743-9213

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Official URL: http://journals.cambridge.org/abstract_S1743921308...

Related URL: http://dx.doi.org/10.1017/S1743921308018401

Abstract

We use a combination of deep, high angular resolution imaging data from the HST/ACS GOODS survey and ground based near-IR Ks images to derive the evolution of the galaxy major merger rate in the redshift range 0.2 ≤ z ≤ 1.2. We select galaxies on the sole basis of their J-band rest-frame, absolute magnitude, which is a good tracer of the stellar mass. We find steep evolution with redshift, with the merger rate α (1+z)2.44±0.39 for optically selected pairs, and α (1+z)2.07±0.74 for pairs selected in the near-IR. Our result is unlikely affected by luminosity evolution which is relatively modest when using a rest-frame J band selection. The major merger rate evolves by a factor ~5 from the current epoch to 1.6×10-3 Mpc-3 Gyr-1 at z ~ 1.2, suggesting that 58%×(0.5 Gyr/τ) of all galaxies with MJ ≤ -19.5 have undergone a major merger in the last ~ 8 Gyr (where τ is the merger timescale). Interestingly, we find no effect on the derived major merger rate due to the presence of the large scale structure at z = 0.735 in the CDFS.We do find some evidence for increased star formation due to possible interactions between members of a pair using Spitzer MIPS 24µm fluxes to estimate the SFR.

Item Type:Article
Source:Copyright of this article belongs to Cambridge University Press.
Keywords:Galaxies: Evolution; Galaxies: Formation; Galaxies: Interactions; Galaxies: Statistics
ID Code:25429
Deposited On:06 Dec 2010 13:25
Last Modified:04 Jun 2011 04:36

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