A1 Journal article – refereed
2S 1553-542: a Be/X-ray binary pulsar on the far side of the Galaxy




List of Authors: Lutovinov AA, Buckley DAH, Townsend LJ, Tsygankov SS, Kennea J
Publisher: OXFORD UNIV PRESS
Publication year: 2016
Journal: Monthly Notices of the Royal Astronomical Society
Journal name in source: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
Journal acronym: MON NOT R ASTRON SOC
Volume number: 462
Number of pages: 7
ISSN: 0035-8711

Abstract
We report the results of a comprehensive analysis of X-ray (Chandra and Swift observatories), optical (Southern African Large Telescope, SALT) and near-infrared (the VVV survey) observations of the Be/X-ray binary pulsar 2S 1553-542. Accurate coordinates for the X-ray source are determined and are used to identify the faint optical/infrared counterpart for the first time. Using VVV and SALTICAM photometry, we have constructed the spectral energy distribution (SED) for this star and found a moderate NIR excess that is typical for Be stars and arises due to the presence of circumstellar material (disc). A comparison of the SED with those of known Be/X-ray binaries has allowed us to estimate the spectral type of the companion star as B1-2V and the distance to the system as >15 kpc. This distance estimation is supported by the X-ray data and makes 2S 1553-542 one of the most distant X-ray binaries within the Milky Way, residing on the far side in the Scutum-Centaurus arm or even further.

Last updated on 2019-29-01 at 10:08