The Physical Origin and Time Lag of Multi-Frequency Flares from SgrA*

Fuente: arXiv
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Autori principali: Jiang, Hong-Xuan, Mizuno, Yosuke, Dihingia, Indu K., Yuan, Feng, Lin, Xi, Fromm, Christian M., Nathanail, Antonios, Younsi, Ziri
Natura: Preprint
Pubblicazione: 2025
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author Jiang, Hong-Xuan
Mizuno, Yosuke
Dihingia, Indu K.
Yuan, Feng
Lin, Xi
Fromm, Christian M.
Nathanail, Antonios
Younsi, Ziri
author_facet Jiang, Hong-Xuan
Mizuno, Yosuke
Dihingia, Indu K.
Yuan, Feng
Lin, Xi
Fromm, Christian M.
Nathanail, Antonios
Younsi, Ziri
contents Sagittarius~A$^*$, the supermassive black hole at the center of our galaxy, exhibits flares across various wavelengths, yet their origins remain elusive. We performed 3D two-temperature General Relativistic Magnetohydrodynamic (GRMHD) simulations of magnetized accretion flows initialized from multi-loop magnetic field configuration onto a rotating black hole and conducted General Relativistic Radiative Transfer (GRRT) calculations considering contributions from both thermal and non-thermal synchrotron emission processes. Our results indicate that the polarity inversion events from the multi-loop magnetic field configurations can generate $138\,\rm THz$ flares consistent with observations with the help of non-thermal emission. By tracing the intensity evolution of light rays in GRRT calculations, we identify the precise location of the flaring region and confirm that it originates from a large-scale polarity inversion event. We observe time delays between different frequencies, with lower-frequency radio flares lagging behind higher frequencies due to plasma self-absorption in the disk. The time delay between near-infrared and 43 GHz flares can reach up to $\sim 50$ min, during which the flaring region gradually shifts outward, becoming visible at lower frequencies. Our study confirms that large-scale polarity inversion in a Standard And Normal Evolution (SANE) accretion flow with a multi-loop initial magnetic configuration can be a potential mechanism driving flares from Sgr~A$^*$.
format Preprint
id arxiv_https___arxiv_org_abs_2507_12789
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle The Physical Origin and Time Lag of Multi-Frequency Flares from SgrA*
Jiang, Hong-Xuan
Mizuno, Yosuke
Dihingia, Indu K.
Yuan, Feng
Lin, Xi
Fromm, Christian M.
Nathanail, Antonios
Younsi, Ziri
High Energy Astrophysical Phenomena
General Relativity and Quantum Cosmology
Sagittarius~A$^*$, the supermassive black hole at the center of our galaxy, exhibits flares across various wavelengths, yet their origins remain elusive. We performed 3D two-temperature General Relativistic Magnetohydrodynamic (GRMHD) simulations of magnetized accretion flows initialized from multi-loop magnetic field configuration onto a rotating black hole and conducted General Relativistic Radiative Transfer (GRRT) calculations considering contributions from both thermal and non-thermal synchrotron emission processes. Our results indicate that the polarity inversion events from the multi-loop magnetic field configurations can generate $138\,\rm THz$ flares consistent with observations with the help of non-thermal emission. By tracing the intensity evolution of light rays in GRRT calculations, we identify the precise location of the flaring region and confirm that it originates from a large-scale polarity inversion event. We observe time delays between different frequencies, with lower-frequency radio flares lagging behind higher frequencies due to plasma self-absorption in the disk. The time delay between near-infrared and 43 GHz flares can reach up to $\sim 50$ min, during which the flaring region gradually shifts outward, becoming visible at lower frequencies. Our study confirms that large-scale polarity inversion in a Standard And Normal Evolution (SANE) accretion flow with a multi-loop initial magnetic configuration can be a potential mechanism driving flares from Sgr~A$^*$.
title The Physical Origin and Time Lag of Multi-Frequency Flares from SgrA*
topic High Energy Astrophysical Phenomena
General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2507.12789