Dynamically Close Galaxy Pairs and Merger Rate Evolution in the CNOC2 Redshift Survey

Details Dynamically Close Galaxy Pairs and Merger Rate Evolution in the CNOC2 Redshift Survey Dynamically Close Galaxy Pairs and Merger Rate Evolution in the CNOC2 Redshift Survey

2001-09-24

arxiv.org/abs/astro-ph/0109428v1

Astronomy and Astrophysics

Astrophysics

40 pages, 8 figures. Accepted for publication in the Astrophysical Journal

Scientific paper

10.1086/324543

We investigate redshift evolution in the galaxy merger and accretion rates, using a well-defined sample of 4184 galaxies with 0.12 < z < 0.55 and R_C < 21.5. We identify 88 galaxies in close (5 < r_p < 20 h^{-1} kpc) dynamical (delta v < 500 km/s) pairs. These galaxies are used to compute global pair statistics, after accounting for selection effects resulting from the flux limit, k-corrections, luminosity evolution, and spectroscopic incompleteness. We find that the number of companions per galaxy (for -21 < M_B^{k,e} < -18) is Nc = 0.0321 +/- 0.0077 at z=0.3. The luminosity in companions, per galaxy, is Lc = 0.0294 +/- 0.0084 x 10^10 h^2 L_sun. We assume that Nc is proportional to the galaxy merger rate, while Lc is directly related to the mass accretion rate. After increasing the maximum pair separation to 50 h^{-1} kpc, and comparing with the low redshift SSRS2 pairs sample, we infer evolution in the galaxy merger and accretion rates of (1+z)^{2.3 +/- 0.7} and (1+z)^{2.3 +/- 0.9} respectively. These are the first such estimates to be made using only confirmed dynamical pairs. When combined with several additional assumptions, this implies that approximately 15% of present epoch galaxies with -21 < M_B < -18 have undergone a major merger since z=1.

Affiliated with

Also associated with

No associations

Rating

Dynamically Close Galaxy Pairs and Merger Rate Evolution in the CNOC2 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 Dynamically Close Galaxy Pairs and Merger Rate Evolution in the CNOC2 Redshift Survey, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dynamically Close Galaxy Pairs and Merger Rate Evolution in the CNOC2 Redshift Survey will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-516076