Approximately one-third of existing {gamma}-ray sources identified by the 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 Fermi unassociated fields, with at least 21 of them being notable for having pulsar-like {gamma}-ray properties as well. We also identify a number of other fields of interest based on various radio and {gamma}-ray selections.

Cone search capability for table J/ApJ/943/51/table2 (The Multi-Survey Catalog (MSC))