Radio recombination lines from external galaxies

Abstract

Using the Very Large Array1 and the Australia Telescope we have searched for the H92 α recombination line from 14 external galaxies and detected the line in 9 of them. All the detected galaxies have starburst nuclei and the line emission is only from the nuclear region. No line was detected in two well known Seyfert II galaxies that were searched to similar sensitivity levels.