Einladung zum Promotionsvortrag von Herrn Sebastian Falkner:
„Modeling accreting X-ray pulsars in curved space timer“
I investigate highly magnetized accreting X-ray pulsars in high mass X-ray binaries (HMXBs). The strong magnetic fields funnel accreted matter onto the magnetic poles of neutron stars forming localized emission regions for beamed X-rays. The observed spectra exhibit a power-law like continuum and also often show broad absorption features caused by cyclotron resonant scattering off electrons. As the pulsars rotate, very characteristic periodic patterns, so called pulse profiles, are observed, which show a broad range of complexity. Because of the extreme compactness of neutron stars, investigating the information contained in observed energy- and phase-resolved flux requires to account for general relativistic effects, like light bending, which can lead to complex and non-intuitive connections between the observed flux and the intrinsic geometry. I combine for the first time a physical treatment of the accretion column with a fully relativistic treatment of the radiative transfer in the neutron star’s gravitational field.
I discuss implications for the observable quantities and the shape of pulse profiles and cyclotron lines. I show that the geometrical setup, the observer inclination and the location of the accretion columns with respect to the rotational axis, has a significant effect on those observables and that general relativistic light bending plays an important role. (Vortrag auf Englisch)
Dem Vortrag schließt sich eine Diskussion von 15 Minuten an. Vortrag und Diskussion sind öffentlich. Diesen Verfahrensteilen folgt ein nicht öffentliches Rigorosum von 45 Minuten.