A southern Milky Way survey at 408 Mc/s

Abstract

A survey of the galactic-plane emission at 408 Mc/s has been carried out over the range 280° < zn < 355°, using the Australian 210 ft radio telescope which has a beamwidth of 47'·5 arc at this frequency. It is found that an abrupt increase in the emission which occurs near zn = 326°, and extends over several degrees of latitude, has a non-thermal spectrum. An estimate of the total radiated power is made, and it is suggested that this feature may be related to the expanding arm of neutral hydrogen whose existence has been demonstrated by H-line studies.