Ground-state OH maser distributions in the Galactic Centre region

TL;DR

This study precisely maps and classifies ground-state OH masers in the Galactic Centre, revealing their distribution patterns among different astrophysical objects.

Contribution

It provides high-accuracy positions and classifications of OH masers in the Galactic Centre, enhancing understanding of their spatial distribution and association with various astrophysical phenomena.

Findings

Distinct distributions of evolved star and star formation OH masers identified

High-precision positions enable better classification of maser sites

Distribution patterns correlate with different astrophysical environments

Abstract

Ground-state OH masers identified in the Southern Parkes Large-Area Survey in Hydroxyl were observed with the Australia Telescope Compact Array to obtain positions with high accuracy ($\sim$1\,arcsec). We classified these OH masers into evolved star OH maser sites, star formation OH maser sites, supernova remnant OH maser sites, planetary nebula OH maser sites and unknown maser sites using their accurate positions. Evolved star and star formation OH maser sites in the Galactic Centre region (between Galactic longitudes of $-5^{\circ}$ to $+5^{\circ}$ and Galactic latitudes of $-2^{\circ}$ and $+2^{\circ}$) were studied in detail to understand their distributions.