Search for unassociated Fermi sources
Abstract
The Fermi Large Area Telescope catalogue 2FGL lists 1872 objects. More than half of them are Active Galatic Nuclei (AGNs) with strong parsec-scale radio emission detectable with VLBI. But 30% of Fermi sources do not have associations and their nature is a mystery. For solving this mystery we launched a project of observing the fields around unassociated sources first with the Australia Telescope Compact Array (ATCA) and the Jansky Very Large Array (VLA) and then following up detected objects with VLBI. This approach allows us to find those gamma-ray sources that are associated with AGNs brighter than 10-20 mJy. Analysis of the completeness of all-sky VLBI surveys shows that the number of bright radio sources with emission from parsec scales is small enough to make the probability of detection of an unrelated object within the Fermi localisation error ellipse negligible. We discuss the status of the program and preliminary results. Early results suggest there exists a population of radio quiet gamma-ray sources not associated with AGNs that show a greater concentration towards the galactic plane.
- Publication:
-
American Astronomical Society Meeting Abstracts #223
- Pub Date:
- January 2014
- Bibcode:
- 2014AAS...22342103P