A Combined Radio Multi-Survey Catalog of Fermi Unassociated Sources

Abstract

Approximately one-third of existing ${\hat{I}}^3$-ray sources identified by the $\text{Fermi Gamma-Ray Space Telescope}$ are considered to be unassociated, with no known counterpart at other frequencies/wavelengths. These sources have been the subject of intense scrutiny and observational effort during the observatory's mission lifetime, and here we present a method of leveraging existing radio catalogs to examine these sources without the need for specific dedicated observations, which can be costly and complex. Via the inclusion of many sensitive low-frequency catalogs we specifically target steep spectrum sources such as pulsars. This work has found steep-spectrum radio sources contained inside 591 $\text{Fermi}$ unassociated fields, with at least 21 of them being notable for having pulsar-like ${\hat{I}}^3$-ray properties as well. We also identify a number of other fields of interest based on various radio and ${\hat{I}}^3$-ray selections.

13 pages, 5 figures, 3 tables, accepted for publication in ApJ