We found 25 galaxies with probable tidal tails in the Hubble Deep Fields North and South at z=0.5-1.5. General characteristics of the selected tidal features are very close to characteristics of tidal tails of local interacting galaxies. Using objects with z=0.5-1.0, we found that volume density of galaxies with tidal tails changes with z as (1+z)^4\pm1. Therefore, we estimated the rate of close encounters between the galaxies of comparable mass leading to the formation of extended tidal structures. If this rate reflects the merger rate, our data support a steeply increasing merger rate at z~1 and consistent with zero curvature universe.
@article{arxiv.astro-ph/9910561,
title = {Interaction rate at z~1},
author = {Vladimir P. Reshetnikov},
journal= {arXiv preprint arXiv:astro-ph/9910561},
year = {2007}
}
Comments
5 pages, 4 figures, accepted for publication in Astron. Astrophys