X-ray spectroscopy of galaxy clusters: beyond the CIE modeling

Abstract

X-ray spectra of galaxy clusters are dominated by the thermal emission from the hot intracluster medium. In some cases, besides the thermal component, spectral models require additional components associated, e.g., with resonant scattering and charge exchange. The latter produces mostly underluminous fine spectral features. Detection of the extra components therefore requires high spectral resolution. The upcoming X-ray missions will provide such high resolution, and will allow spectroscopic diagnostics of clusters beyond the current simple thermal modeling. A representative science case is resonant scattering, which produces spectral distortions of the emission lines from the dominant thermal component. Accounting for the resonant scattering is essential for accurate abundance and gas motion measurements of the ICM. The high resolution spectroscopy might also reveal/corroborate a number of new spectral components, including the excitation by non-thermal electrons, the deviation from ionization equilibrium, and charge exchange from surface of cold gas clouds in clusters. Apart from detecting new features, future high resolution spectroscopy will also enable a much better measurement of the thermal component. Accurate atomic database and appropriate modeling of the thermal spectrum are therefore needed for interpreting the data.

published in Space Science Reviews

References in corpus (17)

• The Quiescent Intracluster Medium in the Core of the Perseus Cluster
• Atomic data and spectral modeling constraints from high-resolution X-ray observations of the Perseus cluster with Hitomi
• Hitomi constraints on the 3.5 keV line in the Perseus galaxy cluster
• Solar abundance ratios of the iron-peak elements in the Perseus Cluster
• Nonthermal phenomena in clusters of galaxies
• Improved measurements of turbulence in the hot gaseous atmospheres of nearby giant elliptical galaxies
• Measurements of resonant scattering in the Perseus cluster core with Hitomi SXS
• Laboratory measurements compellingly support charge-exchange mechanism for the 'dark matter' $\sim$3.5 keV X-ray line
• Spectral Modeling of the Charge-Exchange X-ray Emission from M82
• A volume-limited sample of X-ray galaxy groups and clusters: III. Central abundance drops
• Temperature Structure in the Perseus Cluster Core Observed with Hitomi
• Resonance scattering, absorption and off-centre abundance peaks in clusters of galaxies
• Can Charge Exchange Explain Anomalous Soft X-ray Emission in the Cygnus Loop?
• Suzaku and XMM-Newton Observations of the North Polar Spur: Charge Exchange or ISM Absorption?
• Charge exchange in galaxy clusters
• Observations of asymmetric velocity fields and gas cooling in the NGC 4636 galaxy group X-ray halo
• X-ray Emission from Charge Exchange in the Cygnus Loop SNR

Cited by in corpus (8)

• Constraining Gas Motions in the Intra-Cluster Medium
• Enrichment of the hot intracluster medium: observations
• X-ray spectra of the Fe-L complex
• The Extremely High Dark Matter Halo Concentration of the Relic Compact Elliptical Galaxy Mrk 1216
• The metal content of the hot atmospheres of galaxy groups
• Connecting turbulent velocities and magnetic fields in galaxy cluster simulations with active galactic nuclei jets
• Core to Cosmic Edge: SIMBA-C's New Take on Abundance Profiles in the Intragroup Medium at z = 0
• The clus model in SPEX: projection and resonant scattering effects on the iron abundance and temperature profiles of galaxy clusters