TY - GEN
T1 - High energy radiation from jets and accretion disks near rotating black holes
AU - O'Riordan, Michael
AU - Pe'Er, Asaf
AU - McKinney, Jonathan C.
N1 - Publisher Copyright: © 2017 Author(s).
PY - 2017/1/4
Y1 - 2017/1/4
N2 - We model the low/hard state in X-ray binaries as a magnetically arrested accretion flow, and calculate the resulting radiation using a general-relativistic radiative transport code. Firstly, we investigate the origin of the high-energy emission. We find the following indications of a significant jet contribution at high energies: (i) a pronounced γ-ray peak at ∼ 1023 Hz, (ii) a break in the optical/UV band where the spectrum changes from disk to jet dominated, and (iii) a low-frequency synchrotron peak ≲ 1014 Hz implies that a significant fraction of any observed X-ray and γ-ray emission originates in the jet. Secondly, we investigate the effects of black hole spin on the high-energy emission. We find that the X-ray and γ-ray power depend strongly on spin and inclination angle. Surprisingly, this dependence is not a result of the Blandford-Znajek mechanism, but instead can be understood as a redshift effect. For rapidly rotating black holes, observers with large inclinations see deeper into the hot, dense, highly-magnetized inner regions of the accretion flow. Since the lower frequency emission originates at larger radii, it is not significantly affected by the spin. Therefore, the ratio of the X-ray to near-infrared power is an observational probe of black hole spin.
AB - We model the low/hard state in X-ray binaries as a magnetically arrested accretion flow, and calculate the resulting radiation using a general-relativistic radiative transport code. Firstly, we investigate the origin of the high-energy emission. We find the following indications of a significant jet contribution at high energies: (i) a pronounced γ-ray peak at ∼ 1023 Hz, (ii) a break in the optical/UV band where the spectrum changes from disk to jet dominated, and (iii) a low-frequency synchrotron peak ≲ 1014 Hz implies that a significant fraction of any observed X-ray and γ-ray emission originates in the jet. Secondly, we investigate the effects of black hole spin on the high-energy emission. We find that the X-ray and γ-ray power depend strongly on spin and inclination angle. Surprisingly, this dependence is not a result of the Blandford-Znajek mechanism, but instead can be understood as a redshift effect. For rapidly rotating black holes, observers with large inclinations see deeper into the hot, dense, highly-magnetized inner regions of the accretion flow. Since the lower frequency emission originates at larger radii, it is not significantly affected by the spin. Therefore, the ratio of the X-ray to near-infrared power is an observational probe of black hole spin.
UR - http://www.scopus.com/inward/record.url?scp=85010928618&partnerID=8YFLogxK
U2 - 10.1063/1.4968946
DO - 10.1063/1.4968946
M3 - منشور من مؤتمر
T3 - AIP Conference Proceedings
BT - High Energy Gamma-Ray Astronomy
A2 - Aharonian, Felix A.
A2 - Rieger, Frank M.
A2 - Hofmann, Werner
T2 - 6th International Symposium on High Energy Gamma-Ray Astronomy
Y2 - 11 July 2016 through 15 July 2016
ER -