No CrossRef data available.
Published online by Cambridge University Press: 04 August 2017
About 107 L⊙ of luminosity, mainly in ionizing flux and infrared radiation, emerges from the central pc3 of our Galaxy. This exceeds the luminosity from the corresponding region of most nearby galaxies, though it is surpassed by M82 and NGC 253 (Reike and Lebofsky 1982), but perhaps involves nothing more exotic than a starburst 106 − 107 years ago. But the manifestations of activity at the Galactic Centre that are unambiguously non-thermal in character are at a much lower level: the γ-ray annihilation line (~ 1038 erg s−1) and the compact radio source (~ 1034 erg s−1). I shall comment briefly on these two phenomena, and also suggest an interpretation of the remarkable pseudo-spiral structures revealed by the NeII infrared and the radio-continuum maps. These phenomena relate to the old question (cf. Lynden-Bell and Rees 1971) of whether our Galaxy has ever experienced a more violent phase, leaving a massive collapsed remnant.