The Polarization of X-rays from Warped Black Hole Accretion Disks [HEAP]

http://arxiv.org/abs/1912.00243


It is commonly assumed that in black hole accretion disks the angular momenta of the disk and the black hole are aligned. However, for a significant fraction of stellar mass black holes and supermassive black holes, the momenta may not be aligned. In such systems, the interplay of disk viscosity and general relativistic frame dragging can cause the disk to warp or break into two (or more) distinct planes; this is called the Bardeen-Petterson effect. We have developed a general relativistic ray-tracing code to find the energy spectra and polarization of warped accretion disks, accounting for the emission from the disk and for photons reflecting one or multiple times off the warped accretion disk segments. We find that polarization angle can be used to give a lower limit on the misalignment angle when a previous measurement of the jet, which is thought be aligned with the black hole angular momentum, can be spatially resolved.

Read this paper on arXiv…

Q. Abarr and H. Krawczynski
Tue, 3 Dec 19
21/90

Comments: 10 pages, accepted for publication in ApJ