Number 175 (Story #2), April 25, 1994 by Phillip F. Schewe and Ben Stein|
THE COSMIC X-RAY BACKGROUND (CXB) , the diffuse x-ray glow spread across the sky, probably arises from discrete sources. The Japanese x-ray telescope ASCA has now resolved about 30% of the CXB into individual sources so. At the APS meeting, ASCA scientist Hajime Inoue went further and asserted that there are reasons for believing that the x-ray output of active galaxies---the most energetic category of galaxies---cannot account for the CXB and that most ordinary galaxies, those not previously known for their long-term x-ray emissions, probably contribute to the CXB. Indeed, an ASCA study of one such galaxy, M33, did reveal the presence of a weak central x-ray whose x-ray spectrum resembles that of active galaxies. One inference that can be drawn from this, according to Inoue, is that every galaxy may have a massive black hole at its center.