The Methanol Multibeam Survey

TL;DR

The Methanol Multibeam Survey used a specialized receiver on the Parkes Telescope to detect methanol masers across over 60% of the Galactic plane, providing valuable data on high-mass star formation and Galactic structure.

Contribution

This survey is the first large-scale, systematic mapping of 6.7-GHz methanol masers, offering a comprehensive resource for studying high-mass star formation and Galactic dynamics.

Findings

Detected nearly 1000 methanol maser sources.

Identified regions of enhanced star formation linked to spiral arms.

Provided insights into the interaction between the Galactic bar and 3-kpc arms.

Abstract

A purpose built 7-beam methanol receiver, installed on the Parkes Radio Telescope, was used to survey the Galactic plane for newly forming high mass stars, pinpointed by strong methanol maser emission at 6.7 GHz. The Methanol Multibeam (MMB) survey observed over 60% of the Galactic plane, detecting close to 1000 sources. The MMB survey provides a huge resource for studies of high-mass star formation, an important stage in the evolution of the interstellar medium. The MMB survey is also a valuable resource for investigations into the structure and dynamics of our Galaxy: with narrow velocity ranges of emission (typically only a few km/s) and velocities closely correlated with the systemic velocity of their surrounding molecular clouds, 6.7-GHz methanol masers provide estimates of the spiral arm velocities and their structure. I will discuss the techniques and properties of the MMB survey, before outlining recent results, which include the identification of regions of enhanced star formation believed to be indicative of the origins of the spiral arms and the interaction of the Galactic bar with the 3-kpc arms. I will also discuss the various follow-up programmes including a study of magnetic fields through associated hydroxyl masers.