Multiwavelength study of 1eRASS J085039.9-421151 with eROSITA NuSTAR and X-shooter

The eROSITA instrument on board Spectrum-Roentgen-Gamma has completed four scans of the X-ray sky, leading to the detection of almost one million X-ray sources in eRASS1 only, including multiple new X-ray binary candidates. We report on analysis of the X-ray binary 1eRASS J085039.9-421151, using a ~...

Full description

Saved in:
Bibliographic Details
Published in:arXiv.org 2024-11
Main Authors: Aafia Zainab, Avakyan, Artur, Doroshenko, Victor, Thalhammer, Philipp, Sokolova-Lapa, Ekaterina, Ballhausen, Ralf, Zalot, Nicolas, Stierhof, Jakob, Haemmerich, Steven, Diez, Camille M, Weber, Philipp, Dauser, Thomas, Berger, Katrin, Kretschmar, Peter, Pottschmidt, Katja, Pradhan, Pragati, Islam, Nazma, Maitra, Chandreyee, Coley, Joel B, Blay, Pere, Corbet, Robin H D, Rothschild, Richard E, Wood, Kent, Santangelo, Andrea, Heber, Ulrich, Wilms, Joern
Format: Article
Language:English
Subjects:
Absorption
Black holes
Companion stars
Fluorescence
Infrared analysis
Infrared spectra
Luminosity
Near infrared radiation
Neutron stars
Neutrons
Optical counterparts (astronomy)
X ray binaries
X ray sources
X ray spectra
X ray stars
X-ray astronomy
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The eROSITA instrument on board Spectrum-Roentgen-Gamma has completed four scans of the X-ray sky, leading to the detection of almost one million X-ray sources in eRASS1 only, including multiple new X-ray binary candidates. We report on analysis of the X-ray binary 1eRASS J085039.9-421151, using a ~55\,ks long NuSTAR observation, following its detection in each eROSITA scan. Analysis of the eROSITA and NuSTAR X-ray spectra in combination with X-shooter data of the optical counterpart provide evidence of an X-ray binary with a red supergiant (RSG) companion, confirming previous results, although we determine a cooler spectral type of M2-3, owing to the presence of TiO bands in the optical and near infrared spectra. The X-ray spectrum is well-described by an absorbed power law with a high energy cutoff typically applied for accreting high mass X-ray binaries. In addition, we detect a strong fluorescent neutral iron line with an equivalent width of ~700\,eV and an absorption edge, the latter indicating strong absorption by a partial covering component. It is unclear if the partial absorber is ionised. There is no significant evidence of a cyclotron resonant scattering feature. We do not detect any pulsations in the NuSTAR lightcurves, possibly on account of a large spin period that goes undetected due to insufficient statistics at low frequencies or potentially large absorption that causes pulsations to be smeared out. Even so, the low persistent luminosity, the spectral parameters observed (photon index, \(\Gamma
ISSN:2331-8422