Modelling the 6.7 GHz Methanol Flaring in G358.93-0.03 Using the Maxwell-Bloch Framework
Abstract
We model selected 6.7 GHz methanol flare profiles in G358.93-0.03 using the one-dimensional Maxwell-Bloch framework. The 2019 non-periodic flare, associated with an accretion burst, produced complex single-dish light curves characterized by sharp rises, multiple peaks, secondary structure, and extended decays. For six representative velocity channels, we model each light curve as a sum of scaled intensity responses from effective emitting systems driven by phenomenological pump pulses of fixed width but with component-dependent background rates, amplitudes, and arrival times. The inferred initial inverted column densities correspond to characteristic superradiance timescales TR,0 ≃ 0.3-1.4 d, which are shorter than the adopted dephasing and relaxation timescales, T2 = 6.9 d and T1 = 144.4 d. The fitted components therefore lie in the fast-transient superradiance regime. Existent VLBI observations motivate the possibility that a single-dish velocity channel blends emission from multiple unresolved flaring regions, although these observations are not used as direct fitting constraints. Although the decomposition is not unique, it provides a physically motivated description of the complex flare morphology within a unified Maxwell-Bloch framework.
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BibTeX
@misc{fang2026modelling,
title = {{Modelling the 6.7 GHz Methanol Flaring in G358.93-0.03 Using the Maxwell-Bloch Framework}},
author = {Ningyan Fang and Toktam Rashidi and Yoshinori Yonekura and Vahid Anari and Ross A. Burns and Martin Houde and Fereshteh Rajabi},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.20506},
eprint = {2610.20506},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.20506},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - UNPB
TI - Modelling the 6.7 GHz Methanol Flaring in G358.93-0.03 Using the Maxwell-Bloch Framework
AU - Ningyan Fang
AU - Toktam Rashidi
AU - Yoshinori Yonekura
AU - Vahid Anari
AU - Ross A. Burns
AU - Martin Houde
AU - Fereshteh Rajabi
PY - 2026
DA - 2026/10/14
PB - arXiv
DO - 10.48550/arxiv.2610.20506
UR - https://arxiv.org/abs/2610.20506
AB - We model selected 6.7 GHz methanol flare profiles in G358.93-0.03 using the one-dimensional Maxwell-Bloch framework. The 2019 non-periodic flare, associated with an accretion burst, produced complex single-dish light curves characterized by sharp rises, multiple peaks, secondary structure, and extended decays. For six representative velocity channels, we model each light curve as a sum of scaled intensity responses from effective emitting systems driven by phenomenological pump pulses of fixed width but with component-dependent background rates, amplitudes, and arrival times. The inferred initial inverted column densities correspond to characteristic superradiance timescales T_R,0 ≃ 0.3-1.4 d, which are shorter than the adopted dephasing and relaxation timescales, T_2 = 6.9 d and T_1 = 144.4 d. The fitted components therefore lie in the fast-transient superradiance regime. Existent VLBI observations motivate the possibility that a single-dish velocity channel blends emission from multiple unresolved flaring regions, although these observations are not used as direct fitting constraints. Although the decomposition is not unique, it provides a physically motivated description of the complex flare morphology within a unified Maxwell-Bloch framework.
ER -