Modelling the 6.7 GHz Methanol Flaring in G358.93-0.03 Using the Maxwell-Bloch Framework

arXiv:2610.20506 · astro-ph.SR · Submitted 2026-10-14 · Read on arXiv

astro-ph.SR

Submitted: 2026-10-14

Updated: 2026-10-14

Comments: 10 pages, 4 figures

License: http://creativecommons.org/licenses/by-nc-nd/4.0/

The gist: We model selected 6.7 GHz methanol flare profiles in G358.93-0.03 using the one-dimensional 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 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.

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