2015/06/27 by Manuel Ortega-Rodríguez, Hugo Solís-Sánchez, J. Agustín Arguedas-Leiva +2
Physics and Astronomy · #Accretion (finance) #Accretion disc #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Astrophysics and Cosmic Phenomena #Binary number #Black hole (networking) #Gravitation #Gravitational field #Magnetic field #Magnetohydrodynamics #Spectral line #astro-ph.HE
paper · pdf · doi:10.1088/0004-637x/809/1/15
published as The Astrophysical Journal 809:15 (2015) · 15 pages, 7 figures, accepted for publication in The Astrophysical Journal
arxiv created 2015/06/27 · openalex publication_date 2015/08/04 · arxiv updated 2015/08/07 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Diskoseismology, the theoretical study of normal-mode oscillations in geometrically thin, optically thick accretion disks, is a strong candidate for explaining some quasi-periodic oscillations in the power spectra of many black hole X-ray binary systems. The existence of g-modes, presumably the most robust and visible of the modes, depends on general relativistic gravitational trapping in the hottest part of the disk. As the existence of the required cavity in the presence of magnetic fields has been put into doubt by theoretical calculations, we will explore in greater generality what effect the inclusion of magnetic fields has on the existence of g-modes. We use an analytical perturbative approach on the equations of MHD to assess the impact of such effects. Our main conclusion is that there appears to be no compelling reason to discard g-modes. In particular, the inclusion of a non-zero radial component of the magnetic field enables a broader scenario for cavity non-destruction, especially taking into account recent simulations' saturation values for the magnetic field.