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Wednesday, June 8, 2011

twitter-based astronomy journal club

looking for a practical use for twitter? introducing the astronomy twitter journal club! a paper has been chosen, so read up and participate in the discussion via twitter (#astroJC) next thursday, june 16th at 8pm UT.

(the only impractical aspect for me is that the discussion will take place at 5am sydney time [check your local time here]. oh well... the good thing about twitter is that i can catch up with the discussion when i finally wake up!)


the paper: Gamma Rays From The Galactic Center and the WMAP Haze by Hooper & Linden, 2010

Abstract: Recently, an analysis of data from the Fermi Gamma Ray Space Telescope has revealed a flux of gamma rays concentrated around the inner ~0.5 degrees of the Milky Way, with a spectrum that is sharply peaked at 2-4 GeV. If interpreted as the products of annihilating dark matter, this signal implies that the dark matter consists of particles with a mass between 7.3 and 9.2 GeV annihilating primarily to charged leptons. This mass range is very similar to that required to accommodate the signals reported by CoGeNT and DAMA/LIBRA. In addition to gamma rays, the dark matter is predicted to produce energetic electrons and positrons in the Inner Galaxy, which emit synchrotron photons as a result of their interaction with the galactic magnetic field. In this letter, we calculate the flux and spectrum of this synchrotron emission assuming that the gamma rays from the Galactic Center originate from dark matter, and compare the results to measurements from the WMAP satellite. We find that a sizable flux of hard synchrotron emission is predicted in this scenario, and that this can easily account for the observed intensity, spectrum, and morphology of the "WMAP Haze".

follow along at hashtag: #astroJC
brought to you by @astronomyjc

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