A Unified Maxwell-Bloch Framework to Model Flaring Behaviour in Maser-Hosting Regions

Periodic maser flares in high-mass star-forming regions provide a sensitive probe of the physical conditions in these environments. The methanol maser source G9.62+0.20E is a benchmark object, exhibiting multiple long-lived periodicities and a rich variety of flare morphologies, from highly asymmetric to nearly symmetric profiles across different velocity components. In previous work, we showed that the Maxwell-Bloch equations operating in the fast-transient superradiance regime, driven by narrow periodic pump excitations, can reproduce the asymmetric flares in this source while yielding consistent environmental parameters for the masing gas.

We recently extended that framework by demonstrating that the same Maxwell–Bloch equations can also accounts for the symmetric flares observed in maser-hosting regions such as G9.62+0.20E. Using a common set of physical conditions (e.g. temperature, collisional timescales) across components, we fit representative symmetric and assymetric flares and show that modest changes in the pump modulation and coherence history are sufficient to explain the full range of observed light-curve shapes, without invoking distinct environments for each periodicity. This consistent modelling of both symmetric and asymmetric flares in a single benchmark source strengthens the case for superradiance as a general framework for flaring in maser-hosting regions and motivates its application to other flaring systems.