Ammonia and CO Outflow around 6.7 GHz Methanol Masers

TL;DR

This study investigates ammonia and CO outflows around 6.7 GHz methanol masers, revealing weak correlations suggesting physical association, and introduces new outflow candidates with derived physical properties.

Contribution

It provides new observations of ammonia and CO outflows around methanol masers, identifying 22 new outflow candidates and analyzing their physical properties and correlations.

Findings

22 new outflow candidates identified

Weak correlations between outflow properties and maser luminosities

No significant correlation between ammonia and maser luminosity

Abstract

Single point observations are presented in NH3 (1,1) and (2,2) inversion transitions using the Effelsberg 100 m telescope for a sample of 100 6.7 GHz methanol masers and mapping observations in the 12CO and 13CO (1-0) transitions using the PMO Delingha 13.7 m telescope for 82 sample sources with detected ammonia. A further 62 sources were selected for either 12CO or 13CO line outflow identification, producing 45 outflow candidates, 29 using 12CO and 16 using 13CO data. Twenty-two of the outflow candidates were newly identified, and 23 had trigonometric parallax distances. Physical properties were derived from ammonia lines and CO outflow parameters calculated. Histograms and statistical correlations for ammonia, CO outflow parameters, and 6.7 GHz methanol maser luminosities are also presented. No significant correlation was found between ammonia and maser luminosity. However, weak correlations were found between outflow properties and maser luminosities, which may indicate that outflows are physically associated with 6.7 GHz masers.