Fe K emission lines from accretion disks around neutron star low-mass X-ray binaries
Abstract
Over the last few years, a number of neutron star low-mass X-ray binaries (LMXBs) have been discovered to show broad, asymmetric Fe K emission lines in their X-ray spectra. These lines are generally thought to be the most prominent part of a reflection spectrum, originating in the inner part of the accretion disk where strong relativistic effects can broaden emission lines. Continuum modeling shows that for the majority of observations, a blackbody component (plausibly associated with the boundary layer) dominates the X-ray emission from 8 to 20 keV. Thus, it appears likely that this spectral component produces the majority of the ionizing flux that illuminates the accretion disk. Therefore, we use a physically-motivated blurred reflection model, wherein a blackbody component illuminates the disk. This model fits well in most cases, supporting the idea that the boundary layer illuminates a geometrically thin disk, and that the disk extends close to the neutron star surface over a range of luminosities.
- Publication:
-
39th COSPAR Scientific Assembly
- Pub Date:
- July 2012
- Bibcode:
- 2012cosp...39..269C