Chandra X-ray Observations of the Two Brightest Unidentified High Galactic Latitude Fermi-LAT gamma-ray Sources

TL;DR

This study uses Chandra X-ray observations to identify potential counterparts for two bright, unidentified high-latitude gamma-ray sources from Fermi-LAT, aiming to clarify their nature through multi-wavelength follow-up.

Contribution

First detailed X-ray analysis of these two unidentified gamma-ray sources, providing candidate counterparts for future identification.

Findings

Cataloged X-ray sources within Fermi-LAT error regions.

Identified brightest X-ray sources as potential counterparts.

Highlighted need for optical follow-up to confirm identities.

Abstract

We present Chandra ACIS-I X-ray observations of 0FGL J1311.9-3419 and 0FGL J1653.4-0200, the two brightest high Galactic latitude (|b|>10 deg) gamma-ray sources from the 3 month Fermi-LAT bright source list that are still unidentified. Both were also detected previously by EGRET, and despite dedicated multi-wavelength follow-up, they are still not associated with established classes of gamma-ray emitters like pulsars or radio-loud active galactic nuclei. X-ray sources found in the ACIS-I fields of view are catalogued, and their basic properties are determined. These are discussed as candidate counterparts to 0FGL J1311.9-3419 and 0FGL J1653.4-0200, with particular emphasis on the brightest of the 9 and 13 Chandra sources detected within their respective Fermi-LAT 95% confidence regions. Further follow-up studies, including optical photometric and spectroscopic observations are necessary to identify these X-ray candidate counterparts in order to ultimately reveal the nature of these enigmatic gamma-ray objects.