The nature of GeV Galactic Center excess emission: options and their testability
V ponedeljek, 25. maja 2015, bo dr. Gabrijela Zaharijaš (Univerza v Novi Gorici) predavala o naravi presežka GeV sevanja iz središča Galaksije. Astrodebata bo ob 13. uri v predavalnici F4 na Fakulteti za matematiko in fiziko, Jadranska 19, Ljubljana. Vljudno vabljeni!
Prejšnja predavanja so na razpolago na spletni strani Astrodebate.
Predavanje bo v angleščini.
Abstract:
Several groups have recently claimed evidence for an unaccounted gamma-ray excess over the diffuse backgrounds at few GeV in the Fermi-LAT data in a region around the Galactic Center, consistent with putative signals of long sought for WIMP dark matter particles. However, several conventional astrophysical explanation of this emission appear viable and need to be understood and accounted for, before any robust inference can be made about dark matter signals. In particular, we show that the main features of this excess can be reproduced if they originate in the inverse Compton emission from high-energy electrons injected in a burst event of ~1052-1053 erg roughly O(106) years ago and we discuss the testability of this prediction. Another convincing astrophysical candidate for this emission is an unresolved population of MSP. There have been several works studying this possibility and reaching in some cases opposite conclusions. Here we reassess these claims by adopting a phenomenological approach and make clear predictions for the next generation experiments, which due to their improved angular resolution at few GeV should be able to test the point source origin of the excess.