GRMHD simulations of black hole accretion variabilities: Implications to hard state X-ray binary transients

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Raha, Rohan, Mukhopadhyay, Banibrata, Chatterjee, Koushik
Format: Preprint
Veröffentlicht: 2025
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866917292341723136
author Raha, Rohan
Mukhopadhyay, Banibrata
Chatterjee, Koushik
author_facet Raha, Rohan
Mukhopadhyay, Banibrata
Chatterjee, Koushik
contents Using high-resolution general relativistic magnetohydrodynamic (GRMHD) simulations, we investigate accretion flows around spinning black holes and identify three distinct accretion states. Our results suggest the origin of the complex phenomenology observed across the black hole mass spectrum as the interplay between magnetic and gravitational fields. The magnetically arrested disk (MAD) state, characterized by strong magnetic fields (plasma-$β<< 1$), exhibits powerful jets, highly variable accretion, and significant sub-Keplerian motion. On the other hand, weakly magnetized disks (plasma-$β>> 1$), known as the standard and normal evolution (SANE) state, show steady accretion with primarily winds. An intermediate state bridges the gap between MAD and SANE regimes, with moderate magnetic support (plasma-$β\sim 1$) producing mixed outflow morphologies and complex variability. This unified framework has many implications including its possible connection to extreme variability of GRS 1915+105, particularly in its hard spectral states. It also suggests the possible origin of steady jets of Cyg X-1 and the unusually high luminosities (even super-Eddington based on stellar mass black hole) of HLX-1 without requiring super-Eddington mass accretion rates. Our simulations reveal a hierarchy of timescales that explain the rich variety of variability patterns, with magnetic processes driving transitions between states. Comparing two with three dimensional simulations demonstrates that while quantitative details differ, the qualitative features distinguishing different accretion states remain robust.
format Preprint
id arxiv_https___arxiv_org_abs_2504_17005
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle GRMHD simulations of black hole accretion variabilities: Implications to hard state X-ray binary transients
Raha, Rohan
Mukhopadhyay, Banibrata
Chatterjee, Koushik
High Energy Astrophysical Phenomena
Using high-resolution general relativistic magnetohydrodynamic (GRMHD) simulations, we investigate accretion flows around spinning black holes and identify three distinct accretion states. Our results suggest the origin of the complex phenomenology observed across the black hole mass spectrum as the interplay between magnetic and gravitational fields. The magnetically arrested disk (MAD) state, characterized by strong magnetic fields (plasma-$β<< 1$), exhibits powerful jets, highly variable accretion, and significant sub-Keplerian motion. On the other hand, weakly magnetized disks (plasma-$β>> 1$), known as the standard and normal evolution (SANE) state, show steady accretion with primarily winds. An intermediate state bridges the gap between MAD and SANE regimes, with moderate magnetic support (plasma-$β\sim 1$) producing mixed outflow morphologies and complex variability. This unified framework has many implications including its possible connection to extreme variability of GRS 1915+105, particularly in its hard spectral states. It also suggests the possible origin of steady jets of Cyg X-1 and the unusually high luminosities (even super-Eddington based on stellar mass black hole) of HLX-1 without requiring super-Eddington mass accretion rates. Our simulations reveal a hierarchy of timescales that explain the rich variety of variability patterns, with magnetic processes driving transitions between states. Comparing two with three dimensional simulations demonstrates that while quantitative details differ, the qualitative features distinguishing different accretion states remain robust.
title GRMHD simulations of black hole accretion variabilities: Implications to hard state X-ray binary transients
topic High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2504.17005