Astronomy and Astrophysics – Astrophysics
Scientific paper
Sep 1996
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1996a%26a...313....1s&link_type=abstract
Astronomy and Astrophysics, v.313, p.1-7
Astronomy and Astrophysics
Astrophysics
11
Dark Matter, Galaxy: Halo, Cosmic Rays: Observations, Ism: General
Scientific paper
The γ-ray diffuse emission has been recently observed with unprecedented accuracy by the Compton Gamma Ray Observatory (CGRO) at photon energies in the range between 100MeV and 10GeV. A residual isotropic diffuse radiation is measured for the first time at low galactic latitude, with little variation over different portions of the sky. That measurement translates into a tight constraint on the abundance of diffuse gas in the dark matter halo surrounding our galaxy. If that halo contained significant amounts of gas, cosmic-ray protons originating from the galactic disc would interact with it, yielding a γ-ray flux which CGRO would have observed. By using a diffusion model which correctly reproduces the radial distribution of cosmic-rays along the galactic plane, we infer an upper limit of ~2 to 4% on the fraction of gas in diffuse form or in clouds. The flatter the halo, the stronger the bound. That result only applies in the region where cosmic-rays are confined, i.e., for a galactocentric radius R<20kpc and a height |z|<4kpc. In particular, a thin disc is severely constrained by the γ-ray measurements.
Chardonnet Pascal
Luo Xiaobing
Salati Pierre
Silk Joseph
Taillet Richard
No associations
LandOfFree
The gas deficiency of the galactic 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 The gas deficiency of the galactic halo., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The gas deficiency of the galactic halo. will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1455422