2021/10/13 by Armin Nabizadeh, Sergey S. Tsygankov, Sergey V. Molkov +6
Earth and Planetary Sciences · Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #High-pressure geophysics and materials #Infrared #Nuclear Physics and Applications #Observatory #Phase (matter) #Physics #Pulsar #Spectral line #Stars #Supergiant #Swift #X-ray pulsar #astro-ph.HE
paper · pdf · doi:10.1051/0004-6361/202141608
8 pages, 8 figures, 6 tables, accepted for publication in A&A
arxiv created 2021/10/13 · openalex publication_date 2021/10/25 · arxiv updated 2022/01/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present the results of a detailed investigation of the poorly studied X-ray pulsar 2S 1845−024 based on data obtained at the 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 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 reveals a high hydrogen column density for the source reaching ∼10 24 cm −2 around periastron. Using high-quality Chandra data we were able to obtain an accurate localization of 2S 1845−024 at RA = 18 h 48 m 16 . s 8 and Dec = −2°25 ′ 25 . ″ 1 (J2000), which allowed us to use infrared (IR) data to roughly classify the optical counterpart of the source as an OB supergiant at a distance of ≳15 kpc.