Speaker
Description
A new measurement of a spatially extended gamma-ray signal from the center of M31
was published recently, reporting that the emission broadly resembles the so-called
Galactic center excess of the Milky Way (Ackermann et al. 2017, arXiv:1702.08602).
In this talk we discuss the possibilities that the signal originates from a
population of millisecond pulsars, or alternatively the annihilation of dark matter
particles. As an astrophysical interpretation in terms of millisecond pulsars
appears viable, we derive upper limits on the annihilation cross section in the
$b\bar{b}$/$\tau^-\tau^+-$channel of Weakly Interacting Massive Particles (WIMPs) in a mass range
from 1 GeV to 10 TeV, taking into consideration different spatial dark matter
density profiles and including the effect of substructure and adiabatic contraction.