DOI

https://doi.org/10.48717/3c98-d170

Project

EB114

Title

e-EVN: EB114A Cep A maser flare trigger

Abstract

The Maser Monitoring Organisation (M2O) was established to identify and follow up exceptional, transient behavior in maser sources. In this proposal we request a triggered e/VLBI program to perform fast follow-up observations of sudden enhancements in maser emission by imaging with the EVN. The purpose of our investigation is to use masers as investigative tools of the evolution of the environment of accreting high-mass stars. Accretion events are extremely rare (only 3 published cases to date). Using the property that methanol masers arise in narrow, known ranges of physical conditions we use the locations of maser emitting regions to reveal the radiation and temperature distribution in an accreting high-mass star system. The propagation speed of these masers indicate the thermal evolution of the system following an accretion event. Multi-epoch methanol maser observations can also reveal high-mass protostellar disk properties such as its size, kinematics, overall shape, clumpiness / substructure, and enclosed mass. We demonstrate a case study in this proposal and request more observations to expand the number of well studied high-mass protostellar accretion burst sources.