On the detectability of CO molecules in the Interstellar Medium via X-ray spectroscopy

Abstract

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 analyzed 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 toward 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) > 6x10^{16} cm-2 for typical exposure times

arXiv comment7 pages, 5 figures

References in corpus (23)

• The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI: Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections
• The Milky Way in Molecular Clouds: A New Complete CO Survey
• The Milky Way in X-rays for an outside observer: Log(N)-Log(S) and Luminosity Function of X-ray binaries from RXTE/ASM data
• The distances to Galactic low-mass X-ray binaries: consequences for black hole luminosities and kicks
• Three-Dimensional Distribution of the ISM in the Milky Way Galaxy: II. The Molecular Gas Disk
• The Distance and Interstellar Sight Line to GX339-4
• High-Resolution X-ray Spectroscopy of the Interstellar Medium: Structure at the Oxygen Absorption Edge
• High-Resolution X-ray Spectroscopy of the Interstellar Medium II: Neon and Iron Absorption Edges
• ISM composition through X-ray spectroscopy of LMXBs
• K-shell Photoabsorption of Oxygen Ions
• High-Resolution X-ray Spectroscopy of the Interstellar Medium
• Eddington-limited X-ray Bursts as Distance Indicators. II. Possible Compositional Effects in Bursts from 4U 1636-536
• A superburst from 4U 1254-690
• The Orbital Period of the Ultracompact Low-Mass X-Ray Binary 4U 1543--624
• The morphology of the Milky Way - II. Reconstructing CO maps from disc galaxies with live stellar distributions
• ISMabs: a comprehensive X-ray absorption model for the interstellar medium
• Photoionization modeling of oxygen K absorption in the interstellar medium:the Chandra grating spectra of XTE J1817-330
• A Comprehensive X-ray Absorption Model for Atomic Oxygen
• Can We Trust the Dust? Evidence of Dust Segregation in Molecular Clouds
• Wavelength Measurements of K Transitions of Oxygen, Neon, and Magnesium with X-ray Absorption Lines
• Oxygen, neon, and iron X-ray absorption in the local interstellar medium
• Physical properties of the interstellar medium using high-resolution Chandra spectra: O K-edge absorption
• On the Origin of Highly Ionized X-ray Absorbers Detected in the Galactic X-ray Binaries

Cited by in corpus (10)

• Chandra high-resolution spectra of 4U~1630-47: the disappearance of the wind
• Interstellar oxygen along the line of sight of Cygnus X-2
• Carbon X-ray absorption in the local ISM: fingerprints in X-ray Novae spectra
• Searching for the warm-hot intergalactic medium using XMM-Newton high-resolution X-ray spectra
• High-Resolution X-Ray Spectroscopy of Interstellar Iron Toward Cygnus X-1 and GX 339-4
• 3D mapping of the neutral X-ray absorption in the local interstellar medium: The Gaia and XMM-Newton synergy
• Future Exoplanet Research: Science Questions and How to Address Them
• SRG/eROSITA 3D mapping of the ISM using X-ray absorption spectroscopy
• Argon X-ray absorption in the local ISM
• X-ray absorption of cold gas: Simulating interstellar molecular clouds in the laboratory