Tuesday, 30th August at 10.30am @ the JAC

ABSTRACT: The high-mass star forming region NGC7538 hosts several protostellar objects in different stages of evolution. IRS1 is an Ultra Compact HII region hosting a class II methanol maser emitting at both 6.7 and 12.2 GHz. The maser emission at both frequencies shows a remarkably smooth linear structure both in space and velocity. Through adequate parametrisation of the problem, I show that this structure is uniquely and very accurately modeled as a Keplerian rotating disc around a massive protostar.