title: Possible evidence for MeV dark matter in dwarf spheroidals.
abstract: The observed 511 keV emission from the galactic bulge could be due to very light (MeV) annihilating dark matter particles. To distinguish this hypothesis from conventional astrophysical sources, we study dwarf spheroidals in the region observed by the International Gamma-Ray Astrophysics Laboratory/SPI such as Sagittarius. As these galaxies have comparatively few stars, the prospects for 511 keV emission from standard astrophysical scenarios are minimal. The dwarf spheroidals do, however, contain copious amounts of dark matter. The observation of 511 keV emission from Sagittarius should be a "smoking gun" for MeV dark matter.
authors.affiliation: Astrophysics Department, University of Oxford, Oxford, United Kingdom.
authors.forename: Dan
authors.initials: D
authors.lastname: Hooper
authors.forename: Francesc
authors.initials: F
authors.lastname: Ferrer
authors.forename: Céline
authors.initials: C
authors.lastname: Boehm
authors.forename: Joseph
authors.initials: J
authors.lastname: Silk
authors.forename: Jacques
authors.initials: J
authors.lastname: Paul
authors.forename: N Wyn
authors.initials: NW
authors.lastname: Evans
authors.forename: Michel
authors.initials: M
authors.lastname: Casse