Mapping extragalactic dark matter annihilation with galaxy surveys: A systematic study of stacked group searches

Abstract

Dark matter in the halos surrounding galaxy groups and clusters can annihilate to high-energy photons. Recent advancements in the construction of galaxy group catalogs provide many thousands of potential extragalactic targets for dark matter. In this paper, we outline a procedure to infer the dark matter signal associated with a given galaxy group. Applying this procedure to a catalog of sources, one can create a full-sky map of the brightest extragalactic dark matter targets in the nearby Universe (z 0.03), supplementing sources of dark matter annihilation from within the Local Group. As with searches for dark matter in dwarf galaxies, these extragalactic targets can be stacked together to enhance the signals associated with dark matter. We validate this procedure on mock Fermi gamma-ray data sets using a galaxy catalog constructed from the DarkSky N -body cosmological simulation and demonstrate that the limits are robust, at O(1) levels, to systematic uncertainties on halo mass and concentration. We also quantify other sources of systematic uncertainty arising from the analysis and modeling assumptions. Our results suggest that a stacking analysis using galaxy group catalogs provides a powerful opportunity to discover extragalactic dark matter and complements existing studies of Milky Way dwarf galaxies.

Resummed photon spectra for WIMP annihilation

“…The advantage of such an approach is that we can look at a number of different potential astrophysical sources of DM flux, each associated with partially uncorrelated systematics on their J-factors. In this way we can extend the search beyond the Galactic Center and its large uncertainties to look at potentially cleaner environments such as the Milky Way Dwarfs [166,167] or even galaxy clusters [142,168]. However, note that the effective area of Fermi-LAT drops sharply at TeV energies.…”

Ultra high energy cosmic rays from super-heavy dark matter in the context of large exposure observatories

“…For the Milky Way the parameters are ρ B = 1.187 GeV cm −3 and r B = 10 kpc [28]. The dark matter halos considered are the ones of the DMCat catalog [29,30], which is based on the galaxy group catalogs of Refs. [31,32].…”

Multimessenger Multi-TeV Dark Matter

“…In fact, Fermi LAT among other experiments (e.g. MAGIC [65] ), have allowed to set stringent constraints on the DM particle mass and annihilation cross-section [66,67,68,69,70,71] as well as to increase the number of claims of gamma-ray signatures from DM [72,73,69,74]. However, most of these studies deal with DM particle mass between few MeV and hundreds of GeV.…”