Brightness temperatures of galactic masers observed in the RadioAstron project

TL;DR

This paper reports extremely high brightness temperatures of galactic masers observed with the RadioAstron project, revealing very compact features with unprecedented temperature estimates in star-forming regions.

Contribution

First measurements of brightness temperatures of galactic masers at space baselines, demonstrating the presence of ultra-compact, extremely hot maser features.

Findings

Brightness temperatures range from 10^14 to 10^16 K.

Detected features have angular sizes of 23-60 micro arcsec.

Linear sizes of features are about 4-10 million km.

Abstract

We present estimates of brightness temperature for 5 galactic masers in star-forming regions detected at space baselines. Very compact features with angular sizes of about 23-60 micro arcsec were detected in these regions with corresponding linear sizes of about 4-10 million km. Brightness temperatures range from 1e+14 up to 1e+16 K.