| Title | Astrometric Evidence for a Population of Dislodged AGNs |
| Authors | Makarov, Valeri V.; Frouard, Julien; Berghea, Ciprian T.; Rest, Armin; Chambers, Kenneth C.; Kaiser, Nicholas; Kudritzki, Rolf-Peter; Magnier, Eugene A. |
| Bibcode | 2017ApJ...835L..30M Search ADS ↗ |
| Abstract | We investigate a sample of 2293 ICRF2 extragalactic radio-loud sources with accurate positions determined by VLBI, mostly active galactic nuclei (AGNs) and quasars, which are cross-matched with optical sources in the first Gaia release (Gaia DR1). The distribution of offsets between the VLBI sources and their optical counterparts is strongly non-Gaussian, with powerful wings extending beyond 1 arcsec. Limiting our analysis to only high-confidence difference detections, we find (and publish) a list of 188 objects with normalized variances above 12 and offsets below 1 arcsec. Pan-STARRS stacked and monochromatic images resolve some of these sources, indicating the presence of double sources, confusion sources, or pronounced extended structures. Some 89 high-quality objects, however, do not show any perturbations and appear to be star-like single sources, yet they are displaced by multiples of the expected error from the radio-loud AGN. We conclude that a fraction of luminous AGNs (more than 4%) can be physically dislodged from the optical centers of their parent galaxies. |
| Objects | 188 Objects Search NED ↙ |
