RADIO-CONTINUUM OBSERVATIONS OF SGR-E

The group of compact sources in the direction of the Galactic Centre ( l = 358.7-degrees, b = 0-degrees) known as Sgr E has been observed wit h the Molonglo Observatory Synthesis Telescope at 843 MHz and with the Very Large Array at 1.45 and 4.86 GHz. There are 70 discrete sources in the complex having integrated flux densities S1.4 GHz greater than or similar to 4 mJy, confined to an area of approximately 0.40 deg2. W e determine the radio spectra of 34 of the sources. Of these, most hav e spectral indices (1.45/4.86 GHz) consistent with H II regions. Simpl e models of the compact H II regions and the associated molecular clou d suggest that the complex contains about 20 OB stars, some 2000 M. of ionized gas, about 10(4) M. of stellar mass, and about 2 x 10(6) M. o f Molecular gas. A small proportion of the sources with measured indic es have steep spectra (alpha < -0.5; S is-proportional-to nu(alpha)), and upper limits on S4.86 for several other sources imply steep spectr a. The surface density of steep-spectrum sources and their distributio n of flux densities are consistent with all of them being extragalacti c, and none is an obvious supernova candidate. Sgr E is coincident wit h a region exhibiting a high line-of-sight velocity (-200 km s-1) and lying close to the Galactic Centre. It may represent a small burst of star formation in part of a circumnuclear disc or in matter ejected fr om the Galactic nucleus. The absence of supernovae indicates an age le ss than approximately 5 Myr.