Spectral properties of the accretion discs around rotating black holes

Journal of Astrophysics and Astronomy

SOUMEN MONDAL^2¹  SAMIR MANDAL^1² 

[1] Department of Physics, Jadavpur University, Kolkata 700 032, India.^2;Indian Institute of Space Science and Technology, Thiruvananthapuram 695 547, India.^1

关键词: Accretion disc—radiation spectrum—rotating black hole.;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

We study the radiation properties of an accretion disc around a rotating black hole. We solve the hydrodynamic equations and calculate the transonic solutions of accretion disc in the presence of shocks. Then we use these solutions to generate the radiation spectrum in the presence of radiative heating and coolingprocesses.We present the effect of spin parameter of the black hole on the emitted radiation spectrum. In addition,attention has also been paid to the variation in energy spectral index with Kerr parameter and accretion rate. We find that spectral index becomes harder as the spin parameter changes from negative (accretion disc is counter-rotating with respect to the black hole spin) to a positive value. Finally, we compute and compare the spectral characteristics due to a free-fall flow and a transonic flow. We notice significant differences in highenergy contributions from these two solutions.

【 授权许可】

CC BY