7-11 September 2015
Warsaw, Poland
Europe/Zurich timezone

A search for dark matter annihilation in the newly discovered dwarf galaxy Reticulum 2

8 Sep 2015, 17:30
20m
Rm 207 ()

Rm 207

Speaker

Savvas Koushiappas (Brown University, United States)

Description

I will present results from a search for gamma-ray emission in nine Milky Way satellites recently discovered in the Dark Energy Survey. The nearest of these, Reticulum 2, shows evidence for a signal in public Fermi data. The detected emission is consistent with annihilating dark matter with a particle mass less than a few hundred GeV. Different ways of treating the background yield different significances -- ranging from 2.3 sigma to greater than 3.7 sigma (after trials) -- and I will discuss the caveats involved. Spectroscopic observations of member stars are used to infer the density profile of Reticulum 2, showing that its annihilation signal should be among the largest of the known dwarfs. Finally, I will discuss tests that a dark matter interpretation must pass.

Presentation Materials