Orbital and sub-orbital period determination of the candidate high-mass X-ray binary HD 3191

TL;DR

This study confirms HD 3191 as a high-mass X-ray binary with a roughly 16-day orbital period, linking it to a gamma-ray source, and highlights the need for further investigation into its gamma-ray emission characteristics.

Contribution

It establishes the binary nature of HD 3191 and reports its orbital period, providing new insights into high-energy processes in X-ray binaries with gamma-ray counterparts.

Findings

HD 3191 is a high-mass X-ray binary with a ~16-day orbital period.

Optical observations confirmed the binary nature and periodicities.

No clear orbital cycle detected in gamma-ray data yet.

Abstract

The final aim of this paper is to expand the sparse group of X-ray binaries with gamma-ray counterparts as laboratories to study high-energy processes under physical conditions that periodically repeat. A follow-up of a candidate system has been carried out. We applied both photometric and spectroscopic techniques in the optical domain together with a period analysis using the phase dispersion minimization and CLEAN methods. A tentative period search was also conducted in the gamma-ray domain. Our main result is having established the binary nature of the optical star and X-ray emitter HD 3191 towards the Fermi gamma-ray source 4FGL J0035.8+6131, the last one proposed to be associated with a blazar of an unknown type. An orbital period close to 16 days is reported for HD 3191 together with a likely rotation, or pulsation, period of about 0.6 d. Although no convincing evidence for the orbital cycle has been found in the Fermi light curve up to now, the confirmed presence of a high-mass X-ray binary towards 4FGL J0035.8+6131 now strengthens the need for caution about its true nature.