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Comptonization in X-ray bright neutron star globular cluster systems

M. Guainazzi·A. N. Parmar·T. Oosterbroek
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Abstract

A BeppoSAX survey of bright Neutron Star (NS) systems in globular clusters, together with the results obtained on Galactic LMXRB, suggests that a two-component model is a reasonable description of the 0.1-200 keV spectra. At energies lower than a few keV, a thermal component dominates, either due to the direct view of the NS surface, to the emission of the boundary layer, or to a multi-temperature blackbody originating in the accretion disk. At higher energies, a power-law with an high-energy cutoff is the likely signature of thermal Comptonization of soft X-ray photons, probably produced by the same thermal mechanisms as above. The plasma optical depth (electron temperature) correlates (anticorrelates) with the X-ray luminosity, suggesting that the properties of the Comptonizing plasma are driven by the X-ray energy output.

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M. Guainazzi, A. N. Parmar, T. Oosterbroek. 2000-07-28. Comptonization in X-ray bright neutron star globular cluster systems. https://doi.org/10.1063/1.1434705

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