BURSTING NEUTRON STARS

Thermonuclear burning in the matter accumulated on the surface of an accreting neutron star is unstable under certain conditions, which leads to powerful explosions also called Type I X-ray bursts. This book covers the theory of spectral formation in the atmospheres of neutron stars during these violent events as well as its application to observational data on X-ray bursts. The main goal of the presented study is a proper measurement of the fundamental properties for neutron stars. We take both analytical and numerical approaches to the problem of radiative transfer in X-ray illuminated atmospheres which account for all crucial physical factors such as Comptonization, free-free absorption and emission. We apply our models to the data collected with NASAs Rossi X-ray Timing Explorer mission in order to constrain neutron star masses and radii for five X-ray burster 4U 1728-34, 4U 1820-30, Cygnus X-2, EXO 0748-676 and GS 1826-24. The developed neutron star mass-radius measurement method has a great potential for application to new and archival X-ray data. It can provide scientists with a vital information on various aspects of physics of compact objects.