2023/10/31 by P. Chris Fragile, Peter Anninos, Fragile, P. Chris +5 · 3 citations
Earth and Planetary Sciences · Physics and Astronomy · #Astrophysical Phenomena and Observations #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #High-pressure geophysics and materials #Laser-Plasma Interactions and Diagnostics
paper · pdf · doi:10.48550/arxiv.2311.00028
openalex publication_date 2023/10/31 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present a set of six general relativistic, multi-frequency, radiation magnetohydrodynamic simulations of thin accretion disks with different target mass accretion rates around black holes with spins ranging from non-rotating to rapidly spinning. The simulations use the M1 closure scheme with twelve, independent frequency (or energy) bins ranging logarithmically from 5× 10-3 to 5× 103 keV. The multi-frequency capability allows us to generate crude spectra and energy-dependent light curves directly from the simulations without a need for special post-processing. While we generally find roughly thermal spectra with peaks around 1 to 4 keV, our high-spin cases showed harder than expected tails for the soft or thermally dominant state. This leads to radiative efficiencies that are up to five times higher than expected for a Novikov-Thorne disk at the same spin. We attribute these high efficiencies to the high-energy, coronal emission. These coronae mostly occupy the effectively optically thin regions near the inner edges of the disks and also cover or sandwich the inner ∼ 15 GM/c2 of the disks.