Could a Local Group X-Ray Halo Affect the X-Ray and Microwave Backgrounds?

Abstract

Suto et al. (1996, astro-ph/9602061 and ApJ, 461, L33) have suggested that an X-ray halo in the Local Group might explain both the observed low-energy excess in the X-ray background and the quadrupole anisotropy in the cosmic microwave background. Recent observations of poor groups of galaxies by the ROSAT PSPC set reasonable limits on how extensive and dense such a halo could be. The poor groups most similar to the Local Group do not have a detectable halo, and the upper limits of these observations suggest that any Local Group halo would be nearly two orders of magnitude too tenuous to produce the effects Suto et al. (1996) discuss. In particular, the Sunyaev-Zel'dovich effect cannot contribute significantly to the quadrupole anisotropy measured by COBE.

8 pages, to appear in The Astrophysical Journal Letters, paper can also be obtained at http://hea-www.harvard.edu/~pildis/smio.html

References in corpus (1)

• The X-ray halo of the Local Group and its implications for microwave and soft X-ray background

Cited by in corpus (9)

• X-ray Properties of Groups of Galaxies
• Magnetic fields in Local Group dwarf irregulars
• Extragalactic Foregrounds of the Cosmic Microwave Background: Prospects for the MAP Mission
• Warm Gas and Ionizing Photons in the Local Group (ApJL version)
• Constraints on a Local Group X-ray Halo
• An X-ray and SZ bright diffuse source toward M31: a Local Hot Bridge
• The halo by halo missing baryon problem
• The Kinetic Sunyaev-Zel'dovich effect of the Milky Way Halo
• Search for Hot Gas in the Local Group with ASCA