Contributed Talk - Splinter eROSITA

Tuesday, 13 September 2022, 14:20   (SFG 0140 / virtual eROSITA)

Follow-up of new eROSITA discovered Galactic binary with NuSTAR

Aafia Zainab, Artur Avakyan, Victor Doroshenko, Joern Wilms, Steven Haemmerich
Dr. Karl Remeis Sternwarte Bamberg & ECAP (FAU), Institut fuer Astronomie und Astrophysik Tuebingen (EKUT)

We report on efforts undertaken as part of an eROSTEP (eROsita view of STellar EndPoints) project, which focuses on identification and characterisation of galactic X-ray Binaries. We provide an overview of known galactic XRBs as seen by eROSITA and present the results of follow-up analysis of one of the first galactic XRB candidates discovered in the eROSITA all-sky survey, with NuSTAR (~60ks). Analysis of the broadband X-ray spectrum of eRASSU J084850-420035 observed with NuSTAR shows that the continuum can be well described by comptonization, emission from an accretion disk, or a double-component model describing cold disk accretion. The most likely optical counterpart of the source is identified as a Be star, UCAC2 13726137, ~3'' away. There is no significant evidence of a cyclotron resonant scattering feature and the detection of pulsations is precluded by insufficient counting statistics at low frequencies. Given the predominance of neutron star systems in BeXBs, we suggest that the system is a persistent Be X-ray binary with a slowly spinning neutron star, making it a precursor to the many new XRBs posited to be found with eROSITA.