The X-ray halo of the Local Group and the CMB quadrupole
Abstract
Description
Since recent X-ray observations have revealed that most clusters of galaxies are surrounded by an X-ray emitting gaseous halo, it is reasonable to expect that the Local Group of galaxies has its own X-ray halo. We show that such a halo, with temperature $\sim 1\keV$ and column density $\sim O(10^{21}) {\rm cm}^{-2}$, is a possible source for the excess low-energy component in the X-ray background. The halo should also generate temperature anisotropies in the microwave background via the Sunyaev-Zel'dovich effect. Assuming an isothermal spherical halo with the above temperature and density, the amplitude of the induced quadrupole turns out to be comparable to the COBE data without violating the upper limit on the $y$-parameter.
7 pages. uuencoded, gzipped tar file including LaTeX text and 6 postcript figures (style files, paper.sty and paper2.sty, included). To appear in the Proceedings of the 1st RESCEU international symposium
7 pages. uuencoded, gzipped tar file including LaTeX text and 6 postcript figures (style files, paper.sty and paper2.sty, included). To appear in the Proceedings of the 1st RESCEU international symposium