Extended OH(1720 MHz) Maser Emission from Supernova Remnants

TL;DR

This paper explores the extended OH(1720 MHz) maser emission associated with supernova remnants, highlighting its potential to measure magnetic fields and improve understanding of shock interactions with molecular clouds.

Contribution

It reveals the prevalence of extended maser emission around supernova remnants and discusses modeling techniques to estimate physical conditions and magnetic fields.

Findings

Most supernova remnants with compact masers also show extended emission.

Extended maser emission indicates enhanced OH abundance due to shocks.

Potential to measure magnetic fields via Zeeman splitting over large scales.

Abstract

Compact OH(1720 MHz) masers have proven to be excellent signposts for the interaction of supernova remnants with adjacent molecular clouds. Less appreciated has been the weak, extended OH(1720 MHz) emission which accompanies strong compact maser sources. Recent single-dish and interferometric observations reveal the majority of maser-emitting supernova remnants have accompanying regions of extended maser emission. Enhanced OH abundance created by the passing shock is observed both as maser emission and absorption against the strong background of the remnant. Modeling the observed OH profiles gives an estimate of the physical conditions in which weak, extended maser emission arises. I will discuss how we can realize the utility of this extended maser emission, particularly the potential to measure the strength of the post-shock magnetic field via Zeeman splitting over these large-scales.