Neutron star atmospheres: from bursters to magnetars

V. F. Suleimanov

Učënye zapiski Kazanskogo universiteta. Seriâ Fiziko-matematičeskie nauki, Uchenye Zapiski Kazanskogo Universiteta. Seriya Fiziko-Matematicheskie Nauki, Tome 153 (2011) no. 2, pp. 43-60

Résumé

A brief review of the studies of neutron star atmosphere models performed with the author's participation is presented. These studies are devoted to determination of the nature of emitting surfaces of neutron stars as well as their masses and radii. An extended grid of model atmospheres of the X-ray bursting neutron stars is computed; a new method for determination of neutron star masses and radii, which is based on the calculated model spectra, is suggested. By modeling the atmospheres of magnetic neutron stars ($B\sim10^{10}$–$10^{11}$ G), it is shown that the harmonically spaced absorption features in the X-ray spectrum of the neutron star 1E 1207.4–5209 in the supernova remnant PKS 1209–51/52 may be associated with the quantum peaks in the free-free absorption of plasma in a magnetic field. The nature of the radiating surface of the strongly magnetized ($B\sim10^{13}$–$10^{14}$ G) isolated neutron star RBS 1223 is investigated. It is shown that a thin hydrogen atmosphere above the condensed iron surface explains well the observed pulsed fraction as well as the width and the equivalent width of the absorption line in the observed X-ray spectrum of the neutron star.

Détail

Keywords: neutron stars, stellar model atmospheres, magnetars, radiation transfer, X-rays.