2011/03/13 by Zhang-Zheng Wen, Xian-Zhong Zheng, Ying-He Zhao +1
Physics and Astronomy · #Astronomy and Astrophysical Research #Dwarf galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Population #Redshift #Star formation #Stellar mass #Stellar population #Stellar, planetary, and galactic studies #astro-ph.CO
paper · pdf · doi:10.1007/s10509-011-0882-8
9 pages, 5 figures, Accepted for publication in Astrophysics & Space Science
arxiv created 2011/03/13 · openalex publication_date 2011/11/02 · arxiv updated 2015/05/27 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present the first attempt at measuring the production rate of tidal dwarf galaxies (TDGs) and estimating their contribution to the overall dwarf population. Using HST/ACS deep imaging data from GOODS and GEMS surveys in conjunction with photometric redshifts from COMBO-17 survey, we performed a morphological analysis for a sample of merging/interacting galaxies in the Extended Chandra Deep Field South and identified tidal dwarf candidates in the rest-frame optical bands. We estimated a production rate about 1.4 × 10-5 per Gyr per comoving volume for long-lived TDGs with stellar mass 3 × 108-9 solar mass at 0.5<z<1.1. Together with galaxy merger rates and TDG survival rate from the literature, our results suggest that only a marginal fraction (less than 10%) of dwarf galaxies in the local universe could be tidally-originated. TDGs in our sample are on average bluer than their host galaxies in the optical. Stellar population modelling of optical to near-infrared spectral energy distributions (SEDs) for two TDGs favors a burst component with age 400/200 Myr and stellar mass 40%/26% of the total, indicating that a young stellar population newly formed in TDGs. This is consistent with the episodic star formation histories found for nearby TDGs.