- Author
-
E.M. Cackett
J.M. Miller
D.R. Ballantyne
D. Barret
S. Bhattacharyya
M. Boutelier
M.C. Miller
T.E. Strohmayer
R. Wijnands - Year
- 2010
- Title
- Relativistic lines and reflection from the inner accretion disks around neutron stars
- Journal
- Astrophysical Journal
- Volume | Issue number
- 720 | 1
- Pages (from-to)
- 205-225
- Document type
- Article
- Faculty
- Faculty of Science (FNWI)
- Institute
- Anton Pannekoek Institute for Astronomy (API)
- Abstract
-
A number of neutron star low-mass X-ray binaries (LMXBs) have recently 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. We present a comprehensive, systematic analysis of Suzaku and XMM-Newton spectra of 10 neutron star LMXBs, all of which display broad Fe K emission lines. Of the 10 sources, 4 are Z sources, 4 are atolls, and 2 are accreting millisecond X-ray pulsars (also atolls). The Fe K lines are fit well by a relativistic line model for a Schwarzschild metric, and imply a narrow range of inner disk radii (6-15 GM/c 2) in most cases. This implies that the accretion disk extends close to the neutron star surface over a range of luminosities. 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 also fit the spectra with a 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.
- URL
- go to publisher's site
- Language
- English
- Note
- ID: 434
- Persistent Identifier
- https://hdl.handle.net/11245/1.336375
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