Multibeam Maser Survey of methanol and excited OH in the Magellanic Clouds: new detections and maser abundance estimates

TL;DR

This study conducted a comprehensive survey of the Magellanic Clouds for methanol and excited OH masers, discovering new masers and comparing their populations to those in the Milky Way to understand star formation and chemical abundance differences.

Contribution

First complete survey of the Magellanic Clouds for specific masers, discovering new sources and providing comparative analysis with the Milky Way.

Findings

Discovered a new methanol maser in the LMC at N160a.

Detected a second excited OH maser in N157a.

Found significantly fewer masers in the Magellanic Clouds compared to the Milky Way.

Abstract

We present the results of the first complete survey of the Large and Small Magellanic Clouds for 6668-MHz methanol and 6035-MHz excited-state hydroxyl masers. In addition to the survey, higher-sensitivity targeted searches towards known star-formation regions were conducted. The observations yielded the discovery of a fourth 6668-MHz methanol maser in the Large Magellanic Cloud (LMC), found towards the star-forming region N160a, and a second 6035-MHz excited-state hydroxyl maser, found towards N157a. We have also re-observed the three previously known 6668-MHz methanol masers and the single 6035-MHz hydroxyl maser. We failed to detect emission from either transition in the Small Magellanic Cloud. All observations were initially made using the Methanol Multibeam (MMB) survey receiver on the 64-m Parkes telescope as part of the MMB project and accurate positions have been measured with the Australia Telescope Compact Array (ATCA). We compare the maser populations in the Magellanic Clouds with those of our Galaxy and discuss their implications for the relative rates of massive star-formation, heavy metal abundance, and the abundance of complex molecules. The LMC maser populations are demonstrated to be smaller than their Milky Way counterparts. Methanol masers are under-abundant by a factor of ~45, whilst hydroxyl and water masers are a factor of ~10 less abundant than our Galaxy.