Broad-band analysis of X-ray pulsar 2S 1845$-$024

Abstract

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 $\sim$10${}^{24}$ cm${}^{-2}$ around the periastron. Using high-quality $Chandra$ data we were able to obtain an accurate localization of 2S 1845$-$024 at R.A. = 18${}^h$48${}^m$16${}^s$.8 and Dec. = $-$2${}^{\circ }$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 $\gtrsim$15 kpc.

arXiv comment8 pages, 8 figures, 6 tables, accepted for publication in A&A

References in corpus (20)

• On the Absorption of X-rays in the Interstellar Medium
• The Swift X-ray Telescope
• The Nuclear Spectroscopic Telescope Array (NuSTAR) Mission
• Atomic Data for Astrophysics. II. New Analytic Fits for Photoionization Cross Sections of Atoms and Ions
• Methods and results of an automatic analysis of a complete sample of Swift-XRT observations of GRBs
• Color Transformations for the 2MASS Second Incremental Data Release
• Calibration of X-ray absorption in our Galaxy
• Probing X-ray Absorption and Optical Extinction in the Interstellar Medium Using Chandra Observations of Supernova Remnants
• Multi-wavelength observations of Galactic hard X-ray sources discovered by INTEGRAL. II. The environment of the companion star
• Timing Characteristics of the Hard X-ray Emission from Bright X-ray Pulsars Based on INTEGRAL Data
• On Timing and Spectral Characteristics of the X-ray Pulsar 4U 0115+63: Evolution of the Pulsation Period and the Cyclotron Line Energy
• The Ups & Downs of Accreting X-Ray Pulsars: Decade-long observations with the Fermi Gamma-Ray Burst Monitor
• Hard Spectra of X-Ray Pulsars from INTEGRAL Data
• The Outbursts and Orbit of the Accreting Pulsar GS 1843-02 = 2S 1845-024
• Stable accretion from a cold disc in highly magnetized neutron stars
• Orbital phase resolved spectroscopy of GX 301-2 with MAXI
• Study of the X-ray pulsar IGR J19294+1816 with NuSTAR: detection of cyclotron line and transition to accretion from the cold disc
• First characterization of Swift J1845.7-0037 with NuSTAR
• Properties of the transient X-ray pulsar Swift J1816.7--1613 and its optical companion
• IGR J17463-2854, a Possible Symbiotic Binary System in the Galactic Center Region