[Cosmo-torun] http://arxiv.org/abs/0705.3655

[Bartosz Lew]

hi everyone

this sounds interesting

http://arxiv.org/abs/0705.3655

Title: <b>Evidence Of Dark Matter Annihilations In The WMAP Haze</b><br />
Authors: <b>
<a href="http://arxiv.org/find/astro-ph/1/au:+Hooper_D/0/1/0/all/0/1">Dan 
Hooper</a>, 
<a href="http://arxiv.org/find/astro-ph/1/au:
+Finkbeiner_D/0/1/0/all/0/1">Douglas P. Finkbeiner</a>, 
<a href="http://arxiv.org/find/astro-ph/1/au:+Dobler_G/0/1/0/all/0/1">Gregory 
Dobler</a></b><br />


Comments: 4 pages, 3 figures<br />
<p>The WMAP experiment has revealed an excess of microwave emission from the
region around the center of our Galaxy. It has been suggested that this 
signal,
known as the ``WMAP Haze'', could be synchrotron emission from relativistic
electrons and positrons generated in dark matter annihilations. In this 
letter,
we revisit this possibility. We find that the angular distribution of the WMAP
Haze matches the prediction for dark matter annihilations with a cusped 
density
profile, $\rho(r) \propto r^{-1.2}$ in the inner kiloparsecs. Comparing the
intensity in different WMAP frequency bands, we find that a wide range of
possible WIMP annihilation modes are consistent with the spectrum of the haze
for a WIMP with a mass in the 100 GeV to multi-TeV range. Most interestingly,
we find that to generate the observed intensity of the haze, the dark matter
annihilation cross section is required to be approximately equal to the value
needed for a thermal relic, $\sigma v \sim 3 \times 10^{-26}$ cm$^3$/s. No
boost factors are required. If dark matter annihilations are in fact
responsible for the WMAP Haze, and the slope of the halo profile continues 
into
the inner Galaxy, GLAST is expected to detect gamma rays from the dark matter
annihilations in the Galactic Center if the WIMP mass is less than several
hundred GeV.
</p>
--
Bartosz Lew,
The Graduate School of Science, Nagoya University
email: blew w a.phys.nagoya-u.ac.jp 
tel: +81 52 7892842
www: 
mail: Department of Physics and Astrophysics, Nagoya University,
Chikusa-ku Nagoya 464-8602 Japan