A New 3D Maser Code Applied to Flaring Events

TL;DR

This paper introduces a novel 3D finite-element code for simulating maser sources, analyzing their saturation, apparent size, and variability, with implications for understanding flaring events.

Contribution

The paper presents a new 3D maser simulation code and demonstrates its application to modeling maser saturation, size, and variability, advancing computational astrophysics methods.

Findings

The code accurately models fractional inversions in 3D maser sources.

Apparent size decreases with optical depth as expected.

Rotation can explain some variability but not periodic flaring.

Abstract

We set out the theory and discretization scheme for a new finite-element computer code, written specifically for the simulation of maser sources. The code was used to compute fractional inversions at each node of a 3-D domain for a range of optical thicknesses. Saturation behaviour of the nodes with regard to location and optical depth were broadly as expected. We have demonstrated via formal solutions of the radiative transfer equation that the apparent size of the model maser cloud decreases as expected with optical depth as viewed by a distant observer. Simulations of rotation of the cloud allowed the construction of light-curves for a number of observable quantities. Rotation of the model cloud may be a reasonable model for quasi-periodic variability, but cannot explain periodic flaring.