Massive Protostellar Cores: Galactic Distribution and Dynamics

Massive stars are born in very obscured regions, far away from us and within dense (proto)stellar clusters. For these reasons, the study of the earliest phases of massive star formation requires the use of high angular resolution tools and cold gas probes. Methanol masers and (sub)millimetre continuum emission satisfy these requirements. Methanol masers are exclusively associated with the earliest stages of massive star formation, and appear before the development of any type of HII regions. (Sub)millimetre emission traces cold dust, and potentially reveals the youngest protostellar objects. The combination of both maser and mm continuum observations has allowed us to identify massive protostars in the Galactic plane at different evolutionary phases. SEDs were built for the protostellar cores and massive “class 0” protostars were observed. Moreover, high angular resolution observations of masers were carried out to probe the dynamics (disks, shocks) of the protostellar cores at scales of 1-1000 AU.