More Complex Than You Thought: Geometry, Kinematics, and Fe Abundance of Matter Surrounding the Accretion Flow in 14 Galactic X-Ray Binaries with 56 Chandra HETG Spectra
Abstract
We use the highest resolution X-ray spectral data to date and in the near future (56 observations of 14 famous Galactic X-ray binaries, GXRBs) to probe the geometry, kinematics, and Fe abundance encoded in the narrow, neutral Fe Kα fluorescence emission line and associated reflection continuum. A uniformly spherical X-ray reprocessor with solar Fe abundance is ruled out in 13 out of 14 GXRBs. On the other hand, if nonsolar Fe abundance is assumed, then a spherical geometry is viable in two GXRBs. We apply for the first time an independent, physically self-consistent Compton reflection model with solar Fe abundance and find that it can account for spectra that are inconsistent with a spherical geometry. We further demonstrate that HETG resolves the Fe Kα line in the majority of cases. Our results show that the Chandra HETG view of GXRBs is much more complex and richer than previously thought, paving the way for upcoming X-ray calorimeter missions such as Athena and XRISM.
- Publication:
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AAS/High Energy Astrophysics Division
- Pub Date:
- March 2019
- Bibcode:
- 2019HEAD...1711247T