OH main line masers in the M82 starburst

TL;DR

This study maps OH main line masers in M82, confirming known sources and discovering new ones, revealing their associations with starburst features using high-resolution radio observations.

Contribution

The paper provides the first detailed positional and velocity measurements of OH main line masers in M82, including new detections and their associations with starburst structures.

Findings

Confirmed two known bright masers in M82

Discovered several new main line masers

Most masers are associated with HII regions

Abstract

A study of the distribution of OH gas in the central region of the nearby active starburst galaxy M82 has confirmed two previously known bright masers and revealed several new main line masers. Three of these are seen only at 1665 MHz, one is detected only at 1667 MHz, while the rest are detected in both lines. Observations covering both the 1665 and 1667 MHz lines, conducted with both the Very Large Array (VLA) and the Multi-Element Radio Linked Interferometer Network (MERLIN), have been used to accurately measure the positions and velocities of these features. This has allowed a comparison with catalogued continuum features in the starburst such as HII regions and supernova remnants, as well as known water and satellite line OH masers. Most of the main line masers appear to be associated with known HII regions although the two detected only at 1665 MHz are seen along the same line of sight as known supernova remnants.