A rare outburst from the stealthy BeXRB system Swift J0549.7-6812
arXiv:2306.17098 · doi:10.1093/mnras/stad1987
Abstract
Swift J0549.7-6812 is an Be/X-ray binary system (BeXRB) in the Large Magellanic Cloud (LMC) exhibiting a 6s pulse period. Like many such systems the variable X-ray emission is believed to be driven by the underlying behaviour of the mass donor Be star. In this paper we report on X-ray observations of the brightest known outburst from this system which reached a luminosity of 8 x 10^37 erg/s. These observations are supported by contemporaneous optical photometric observations, the first reported optical spectrum, as well as several years of historical data from OGLE and GAIA. The latter strongly suggest a binary period of 46.1d. All the observational data indicate that Swift J0549.7-6812 is a system that spends the vast majority of its time in X-ray quiescence, or even switched off completely. This suggests that occasional observations may easily miss it, and many similar systems, and thereby underestimate the massive star evolution numbers for the LMC.
arXiv comment7 pages, 11 figures
References in corpus (18)
- The Swift X-ray Telescope
- Intrinsic Colors, Temperatures, and Bolometric Corrections of Pre-Main Sequence Stars
- The observed properties of dwarf galaxies in and around the Local Group
- Calibration of X-ray absorption in our Galaxy
- An eclipsing binary distance to the Large Magellanic Cloud accurate to 2 per cent
- The Swift/BAT Hard X-ray Transient Monitor
- Gaia broad band photometry
- A natural explanation for periodic X-ray outbursts in Be/X-ray binaries
- A 2dF survey of the Small Magellanic Cloud
- OGLE-ing the Magellanic System: Optical Reddening Maps of the Large and Small Magellanic Cloud from Red Clump Stars
- High-Mass X-ray binaries in the Small Magellanic Cloud
- MN48: a new Galactic bona fide luminous blue variable revealed by Spitzer and SALT
- Spin period change and the magnetic fields of neutron stars in Be X-ray binaries in the Small Magellanic Cloud
- Estimating Be Star Disk Radii using H-alpha Emission Equivalent Widths
- Catalogue of Be/X-ray binary systems in the Small Magellanic Cloud: X-ray, optical & IR properties
- The First Year of S-CUBED: The Swift Small Magellanic Cloud Survey
- Modelling decretion discs in Be/X-ray binaries
- SRG/eROSITA-triggered XMM-Newton observations of three Be/X-ray binaries in the LMC: Discovery of X-ray pulsations