Class I methanol masers in low-mass star formation regions

TL;DR

This paper reviews the properties of low-mass star formation region Class I methanol masers, highlighting their similarities to massive star formation masers and their potential for detailed study due to proximity.

Contribution

It provides a comprehensive review of low-mass methanol masers, emphasizing their properties, association with outflows, and potential for advancing understanding of Class I masers.

Findings

LMMIs are associated with postshock gas in outflows.

They share properties with massive star formation masers.

EVLA observations reveal unresolved spots with high brightness temperatures.

Abstract

We present a review of the properties of Class I methanol masers detected in low-mass star forming regions (LMSFRs). These masers, henceforth called LMMIs, are associated with postshock gas in the lobes of chemically active outflows in LMSFRs NGC1333, NGC2023, HH25, and L1157. LMMIs share the main properties with powerful masers in regions of massive star formation and are a low-luminosity edge of the total Class I maser population. However, the exploration of just these objects may push forward the exploration of Class I masers, since many LMSFRs are located only 200--300 pc from the Sun, making it possible to study associated objects in detail. EVLA observations with a $0.2"$ spatial resolution show that the maser images consist of unresolved or barely resolved spots with brightness temperatures up to $5\times 10^5$ K. The results are "marginally" consistent with the turbulent model of maser emission.