X-ray absorption spectroscopy of the hot interstellar medium near the Galactic center

Abstract

In this thesis, we present a research carried out on the hot phase of the Interstellar Medium (ISM), which is an important tracer of star formation and supernova activity and ultimately of Galaxy evolution. High-resolution X-ray spectroscopy was used to asses the homogeneity and temperature of the hot phase of the ISM near the Galactic center as function of the line of sight. Twelve background X-ray sources were used to attain these properties. An indication of hot gas with a temperature of about 10^7 K and hydrogen column densities of about 10^21 - 10^22 cm^-2 has been detected. This agrees with theoretical expectations. However, the quality of the data did not allow stringent constraints on the gas parameters. We discuss possible factors which influenced our analysis.