Multiwavelength Observations of Gamma-ray Binary Candidates

TL;DR

This study investigates potential gamma-ray binary candidates by conducting multiwavelength observations, but finds no high-energy emission from the proposed Be star counterparts, instead exploring other possible X-ray sources.

Contribution

The paper provides multiwavelength observational data to evaluate gamma-ray binary candidates and refines the identification process by ruling out initial Be star associations.

Findings

No high-energy emission detected from the Be stars HD 99771 and HD 165783.

Other X-ray sources in the field may be potential counterparts.

Refined understanding of gamma-ray binary candidate identification.

Abstract

A rare group of high mass X-ray binaries (HMXBs) are known that also exhibit MeV, GeV, and/or TeV emission ("gamma-ray binaries"). Expanding the sample of gamma-ray binaries and identifying unknown Fermi sources are currently of great interest to the community. Based upon their positional coincidence with the unidentified Fermi sources 1FGL J1127.7-6244c and 1FGL J1808.5-1954c, the Be stars HD 99771 and HD 165783 have been proposed as gamma-ray binary candidates. During Fermi Cycle 4, we have performed multiwavelength observations of these sources using XMM-Newton and the CTIO 1.5m telescope. We do not confirm high energy emission from the Be stars. Here we examine other X-ray sources in the field of view that are potential counterparts to the Fermi sources.