A Point-Source Catalog from Swift Observations of Unidentified Fermi Sources

TL;DR

This paper provides an X-ray point source catalog from Swift observations covering unidentified Fermi sources, aiding future identification efforts by offering positional and property data for potential counterparts.

Contribution

It presents the first comprehensive catalog of X-ray sources associated with a majority of unidentified Fermi gamma-ray sources, enhancing multi-wavelength identification strategies.

Findings

18 X-ray point sources identified within Fermi error contours

Potential counterparts discussed for seven specific Fermi sources

Catalog supports future observational follow-up efforts

Abstract

We present X-ray point source catalogs obtained from archival Swift observations that have partially or fully covered the 95% confidence error contour of unidentified Fermi sources. In total, 21 out of 37 unidentified Fermi sources have been observed by the X-Ray Telescope (XRT) on board the Swift observatory. Basic properties such as position, positional errors, count rates, and hardness ratios are derived for a total of 18 X-ray point sources found in the sample. From these detections, we discuss potential counterparts to 0FGL J0910.2-5044, 0FGL J1045.6-5937, 0FGL J1115.8-6108, 0FGL J1231.5-1410, 0FGL J1326.6-5302, 0FGL J1604.0-4904, and 0FGL J1805.3-2138. The catalog will assist observers planning future programs to identify 0FGL sources without obvious counterparts.