PIRSA:09060052  ( MP4 Medium Res , MP3 , PDF ) Which Format?
The origin of the cosmic ray positron/electron excesses in light of the recent observations
Speaker(s): Hasan Yuksel
Abstract: The spectra of cosmic ray electrons and positrons should have contributions from known sources such as particles accelerated in supernova remnants and from the cosmic rays interactions. Besides these guaranteed contributions, any evidence for an additional component may carry hints of a new phenomenon. Most recently PAMELA and ATIC experiments hinted an overabundance of these particles as compared to model expectations and generated much interest on astrophysical and exotic explanations. I will first examine the implications of the recent detection of extended, multi-TeV gamma-ray emission from Geminga pulsar wind nebula, which reveals the existence of an ancient/nearby cosmic ray accelerator that can also plausibly account for the observed excess. Next, I will focus on a possibility that these particles might be produced through dark matter decays/annihilations within the halo of our Galaxy. I will conclude by reviewing implications of these scenarios for several categories of upcoming Gamma Ray/Neutrino observatories including Fermi and IceCube.
Date: 11/06/2009 - 2:40 pm
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