Probing the spectral dependence of QPOs in accreting X-ray pulsars.
Abstract
If the absorption column density towards an accreting X-ray pulsar is not very large, it usually shows a soft excess component in the X-ray spectrum along with the hard power-law component. The soft excess is believed to be produced in the inner accretion disk by reprocessing the hard X-rays that originate at the accretion column of the neutron star. The pulse profiles in the spectral ranges corresponding to the two spectral components, having different origins, are often dissimilar. As the accretion disk in such systems has a relatively large inner radius, some of these sources also exhibit quasi-periodic oscillations(QPOs) at a few mHz. We will report the results from an investigation of the QPOs in the soft and hard X-rays of several X-ray pulsars from XMM-Newton pointed observations. This is the first comparative study of QPOs in the context of the two spectral components in accretion powered X-ray pulsars, which has important implications for the origin of the QPOs in accretion powered X-ray pulsars.
- Publication:
-
44th COSPAR Scientific Assembly. Held 16-24 July
- Pub Date:
- July 2022
- Bibcode:
- 2022cosp...44.2373M