Journal
ASTRONOMICAL JOURNAL
Volume 122, Issue 1, Pages 63-82Publisher
IOP PUBLISHING LTD
DOI: 10.1086/321127
Keywords
galaxies : evolution; galaxies : interactions; galaxies : nuclei; galaxies : star clusters; infrared radiation
Categories
Ask authors/readers for more resources
We perform photometric measurements on a large HST snapshot imaging survey sample of 97 ultraluminous infrared galaxies (ULIRGs). We select putative nuclei from bright clumps in all the sample targets, mainly based on a quantitative criterion of I-band luminosity as well as the global and local morphological information. All the sources are then classified into three categories with multiple, double, and single nucleus/nuclei. The resultant fractions of multiple, double, and single nucleus/nuclei ULIRGs are 18%, 39%, and 43%, respectively. This supports the multiple merger scenario as a possible origin of ULIRGs, in addition to the commonly accepted pair merger model. Further statistical studies indicate that the AGN fraction increases from multiple (36%) to double (65%) and then to single (80%) nucleus/nuclei ULIRGs. For the single nucleus category, there is a high-luminosity tail in the luminosity distribution, which corresponds to a Seyfert 1/QSO excess. This indicates that active galactic nuclei tend to appear at final merging stage. For multiple/double nuclei galaxies, we also find a high fraction of very close nucleus pairs (e.g., 3/4 for those separated by less than 5 kpc). This strengthens the conclusion that systems at late merging phase preferentially host ULIRGs.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available