Companions of Low-Redshift Quasars
Abstract
Using imaging data from a relatively complete subset of low-redshift radio-quiet quasars, the frequency of finding associated companion galaxies of the quasars is determined statistically. With an average completeness limit of Mr of about -19, it is found that about 40 percent of the quasars have at least one close physical companion within a projected distance of 100 kpc. The percentage of quasars with detected companions is consistent with all quasars in the sample having a companion of luminosity brighter than about -16.5 mag. It is estimated that the frequency of finding close companions to quasars is about six times higher than that expected for field galaxies. This frequency is similar to that found for lower-luminosity Seyfert galaxies. The properties of the companions appear to be uncorrelated with the level of activity in the quasars. This suggests that, for radio-quiet quasars, the companions act mainly as triggers of the activity and are probably not a strong determining factor of the detailed properties of the quasars.
- Publication:
-
The Astronomical Journal
- Pub Date:
- December 1987
- DOI:
- 10.1086/114578
- Bibcode:
- 1987AJ.....94.1461Y
- Keywords:
-
- Galactic Structure;
- Quasars;
- Red Shift;
- Spectrum Analysis;
- Statistical Analysis;
- Radio Spectra;
- Seyfert Galaxies;
- Stellar Activity;
- Stellar Luminosity;
- Astronomy;
- QUASARS