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QPOs from the Viscous Transonic Accretion Flow Around a Spinning Black Hole

High Energy Astrophysical Phenomena 2026-04-22 v1

Abstract

We investigate the dynamics of transonic advective accretion flows around spinning black holes in the presence of viscosity. The spacetime of a Kerr black hole is approximated using a pseudo-potential. We study viscously driven shock oscillations over a range of black hole spin parameters. Our results show that the frequency range of quasi-periodic oscillations (QPOs) obtained from the power density spectra depends strongly on the black hole spin. Low-spin systems predominantly exhibit low-frequency QPOs, whereas rapidly rotating black holes (0.9) produce QPOs spanning a broad range from low to high frequencies, comparable to those observed in black hole X-ray binaries. We further obtain a correlation between the QPO frequency and the power-law photon index by computing the spectrum for a 10 solar mass black hole.

Keywords

Cite

@article{arxiv.2604.19692,
  title  = {QPOs from the Viscous Transonic Accretion Flow Around a Spinning Black Hole},
  author = {Sanjit Debnath and Indranil Chattopadhyay and Soumyadip Mandal and Raj Kishor Joshi and Priyesh Kumar Tripathi and M. Saleem Khan},
  journal= {arXiv preprint arXiv:2604.19692},
  year   = {2026}
}

Comments

13 pages, 8 figures