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Low-resolution, radio-intensity maps of the Galactic Center are dominated by two structures: the extended, nonthermal region between ℓ = 0°.0 and 0°.3 called Sagittarius A(East); and the bright thermal source at ℓ = −0°.05 and b = −0°.05 called Sagittarius A(West). SgrA(East) is probably a supernova remnant. SgrA(West) is a dense, gaseous region which is the very center of our Galaxy. Within SgrA(West) is a pc-sized cluster of infrared sources — late-type stars and gas condensations — swirling about with a dispersion of 250 km s−1. The cluster contains a unique radio source with the following properties: a size not exceeding 1015 cm, a radio luminosity exceeding 1034 erg s−1, and rather stable properties on a time scale of 108 s. This compact, nonthermal object (SgrAcn below) may be surrounded by a 0.1pc infrared source. Models for SgrAcn include both 106 M⊙ black holes related to the central objects in radio galaxies and quasars (Oort 1977, van Buren 1978) and 1 M⊙ degenerate stars related to pulsars and X-ray binaries (Reynolds and McKee 1980). We present below the radio intensity spectrum as a basic datum for further development of either class of models.
