2016/06/07 by Katerine Joachimi, Efraín Gatuzz, Javier A. García +2
Physics and Astronomy · #Absorption (acoustics) #Absorption spectroscopy #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Star Formation Studies #Galaxy #Interstellar medium #Line (geometry) #Line-of-sight #Monte Carlo method #Optics #Physics #Spectral line #Spectrometer #Spectroscopy #Stellar, planetary, and galactic studies #X-ray spectroscopy #astro-ph.HE
paper · pdf · doi:10.1093/mnras/stw1371
7 pages, 5 figures
arxiv created 2016/06/07 · openalex publication_date 2016/06/09 · arxiv updated 2016/07/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present a study of the detectability of CO molecules in the Galactic interstellar medium using high-resolution X-ray spectra obtained with the XMM–Newton Reflection Grating Spectrometer. We analysed 10 bright low mass X-ray binaries (LMXBs) to study the CO contribution in their line of sights. A total of 25 observations were fitted with the ISMabs X-ray absorption model which includes photoabsorption cross-sections for O i, O ii, O iii and CO. We performed a Monte Carlo (MC) simulation analysis of the goodness of fit in order to estimate the significance of the CO detection. We determine that the statistical analysis prevents a significant detection of CO molecular X-ray absorption features, except for the lines of sight towards XTE J1718-330 and 4U 1636−53. In the case of XTE J1817-330, this is the first report of the presence of CO along its line of sight. Our results reinforce the conclusion that molecules have a minor contribution to the absorption features in the O K-edge spectral region. We estimate a CO column density lower limit to perform a significant detection with XMM–Newton of N(CO) > 6 × 1016 cm−2 for typical exposure times.