We present results of detailed investigation of the poorly studied X-ray pulsar 2S 1845−024 based on the data obtained with NuSTAR observatory during the type I outburst in 2017. Neither pulse phase-averaged, nor phase-resolved spectra of the source show evidence for a cyclotron absorption feature. We also used the data obtained from other X-ray observatories (Swift, XMM−Newton and Chandra) to study the spectral properties as a function of orbital phase. The analysis revealed a high hydrogen column density for the source reaching ∼1024 cm−2 around the periastron. Using high-quality Chandra data we were able to obtain an accurate localization of 2S 1845−024 at R.A. = 18h48m16s.8 and Dec. = −2∘25'25".1 (J2000) that allowed us to use infrared (IR) data to roughly classify the optical counterpart of the source as an OB supergiant at the distance of ≳15 kpc.
@article{arxiv.2110.06642,
title = {Broad-band analysis of X-ray pulsar 2S 1845$-$024},
author = {Armin Nabizadeh and Sergey S. Tsygankov and Sergey V. Molkov and Dmitri I. Karasev and Long Ji and Alexander A. Lutovinov and Juri Poutanen},
journal= {arXiv preprint arXiv:2110.06642},
year = {2022}
}
Comments
8 pages, 8 figures, 6 tables, accepted for publication in A&A