Answers are grounded in this paper and cite their sources.
The main line transitions of hydroxyl (OH) have been detected in emission in the peculiar galaxy IC 4553. The 1667 and 1665 MHz transitions appear in a ratio of 4.2:1, and both have a radial velocity of 5375 km/sec and a full width at half-maximum of 108 km/sec. This is the first detection of broad OH emission in an external galaxy. The features are probably due to stimulated emission from many H II/OH masers in the active nuclear region of the galaxy. It is suggested that IC 4553 is a starburst galaxy.
No takes yet. Share an insight, caveat, or question.
Baan et al. (1982) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: