Constraints on a Local Group X-ray Halo

Details Constraints on a Local Group X-ray Halo Constraints on a Local Group X-ray Halo

2001-05-28

arxiv.org/abs/astro-ph/0105487v1

Astronomy and Astrophysics

Astrophysics

24 pages, 16 figures. Accepted for publication in the Astrophysical Journal

Scientific paper

10.1086/322380

A simple model for a hot Local Group halo is constructed, using the standard beta-model for the halo density and by choosing model parameters based on all available observations of X-ray emission in other groups of galaxies and on optical data on Local Group morphology. From the predicted X-ray intensities, total Local Group mass, and central cooling time of the halo, we derive very conservative upper limits on the central halo density N_0 and global temperature T of N_0 = 5e-4 cm-3 and kT = 0.5 keV, irrespective of realistic values of the density profile parameters r_c and beta. A typical poor group value of beta = 0.5 requires kT < 0.15 keV and N_0 < 1e-4 cm-3, from which it is concluded that the Local Group is very unlikely to possess a significant X-ray halo. The prospects for further constraining of halo parameters from UV absorption line observations are considered. We explicitly calculate the ability of the halo to distort the cosmic microwave background (CMB) in terms of the resulting CMB temperature variations and multipole anisotropies.

Affiliated with

Also associated with

No associations

Rating

Constraints on a Local Group X-ray Halo does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Constraints on a Local Group X-ray Halo, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Constraints on a Local Group X-ray Halo will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-313212