Where do Wet, Dry, and Mixed Galaxy Mergers Occur? A Study of the Environments of Close Galaxy Pairs in the DEEP2 Galaxy Redshift Survey

Details Where do Wet, Dry, and Mixed Galaxy Mergers Occur? A Study of the Environments of Close Galaxy Pairs in the DEEP2 Galaxy Redshift Survey Where do Wet, Dry, and Mixed Galaxy Mergers Occur? A Study of the Environments of Close Galaxy Pairs in the DEEP2 Galaxy Redshift Survey

2010-01-25

arxiv.org/abs/1001.4560v1

Astrophysical Journal 718 (2010) 1158-1170

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

14 pages, 7 figures, 2 tables, submitted to ApJ, revised according to the referee's comments

Scientific paper

We study the environment of wet, dry, and mixed galaxy mergers at 0.75 < z < 1.2 using close pairs in the DEEP2 Galaxy Redshift Survey. We find that the typical environment of mixed and dry merger candidates is denser than that of wet mergers, mostly due to the color-density relation. While the galaxy companion rate (Nc) is observed to increase with overdensity, using N-body simulations we find that the fraction of pairs that will eventually merge decreases with the local density, predominantly because interlopers are more common in dense environments. After taking into account the merger probability of pairs as a function of local density, we find only marginal environment dependence of the fractional merger rate for wet mergers over the redshift range we have probed. On the other hand, the fractional dry merger rate increases rapidly with local density due to the increased population of red galaxies in dense environments. We also find that the environment distribution of K+A galaxies is similar to that of wet mergers alone and of wet+mixed mergers, suggesting a possible connection between K+A galaxies and wet and/or wet+mixed mergers. We conclude that, as early as z ~ 1, high-density regions are the preferred environment in which dry mergers occur, and that present-day red-sequence galaxies in overdense environments have, on average, undergone 1.2+-0.3 dry mergers since this time, accounting for (38+-10)% of their mass accretion in the last 8 billion years. Our findings suggest that dry mergers are crucial in the mass-assembly of massive red galaxies in dense environments, such as Brightest Cluster Galaxies (BCGs) in galaxy groups and clusters.

Affiliated with

Also associated with

No associations

Rating

Where do Wet, Dry, and Mixed Galaxy Mergers Occur? A Study of the Environments of Close Galaxy Pairs in the DEEP2 Galaxy Redshift Survey does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Where do Wet, Dry, and Mixed Galaxy Mergers Occur? A Study of the Environments of Close Galaxy Pairs in the DEEP2 Galaxy Redshift Survey, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Where do Wet, Dry, and Mixed Galaxy Mergers Occur? A Study of the Environments of Close Galaxy Pairs in the DEEP2 Galaxy Redshift Survey will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-643597