Peculiar objects towards 3FGL J0133.3+5930: an eclipsing Be star and an active galactic nucleus

TL;DR

This study investigates unassociated gamma-ray sources in the galactic plane, identifying a peculiar eclipsing Be star and a likely active galactic nucleus within the error region of 3FGL J0133.3+5930, to understand their potential as gamma-ray emitters.

Contribution

It reports the discovery of an eclipsing Be star and a probable active galactic nucleus as potential counterparts to a gamma-ray source, expanding the known types of gamma-ray emitting systems.

Findings

Discovered an eclipsing binary star TYC 3683-985-1.

Identified a likely low-power active galactic nucleus at z=0.1143.

Proposed the AGN as a possible gamma-ray source, but the star remains a candidate.

Abstract

Aims. We aim to contribute to the identification of unassociated gamma-ray sources in the galactic plane in order to enlarge the currently known population of gamma-ray binaries and related systems, such as radio emitting X-ray binaries and microquasars. These objects are currently regarded as excellent test beds for the understanding of high energy phenomena in stellar systems. Methods. Potential targets of study are selected based on cross-identification of the 3rd Fermi Large Area Telescope catalogue with historical catalogues of luminous stars often found as optical counterparts in known cases. Follow-up observations and analysis of multi-wavelength archival data are later used to seek further proofs of association beyond the simple positional agreement. Results. Current results enable us to present here the case of the Fermi source 3FGL J0133.3+5930 where two peculiar objects have been discovered inside its region of uncertainty. One of them is the star TYC 3683-985-1 (LS I +59 79) whose eclipsing binary nature is reported in this work. The other one is the X-ray source SWIFT J0132.9+5932, that we found to be a likely low-power Active Galactic Nucleus at z = 0:1143 \pm 0:0002. If this second object is of blazar type, it could easily account for the observed gamma-ray photon flux. However, this is not confirmed at present, thus rendering still open the star system TYC 3683-985-1 as an alternative counterpart candidate to the Fermi source.