Bibcode
Cuesta, A. J.; Jeltema, T. E.; Zandanel, F.; Profumo, S.; Prada, F.; Yepes, G.; Klypin, A.; Hoffman, Y.; Gottlöber, S.; Primack, J.; Sánchez-Conde, M. A.; Pfrommer, C.
Bibliographical reference
The Astrophysical Journal Letters, Volume 726, Issue 1, article id. L6 (2011).
Advertised on:
1
2011
Citations
28
Refereed citations
21
Description
We present all-sky simulated Fermi maps of γ-rays from dark matter
(DM) decay and annihilation in the local universe. The DM distribution
is obtained from a constrained cosmological simulation of the
neighboring large-scale structure provided by the CLUES project. The DM
fields of density and density squared are then taken as an input for the
Fermi observation simulation tool to predict the γ-ray photon
counts that Fermi would detect in 5 years of an all-sky survey for given
DM models. Signal-to-noise ratio (S/N) sky maps have also been obtained
by adopting the current Galactic and isotropic diffuse background models
released by the Fermi Collaboration. We point out the possibility for
Fermi to detect a DM γ-ray signal in local extragalactic
structures. In particular, we conclude here that Fermi observations of
nearby clusters (e.g., Virgo and Coma) and filaments are expected to
give stronger constraints on decaying DM compared to previous studies.
As an example, we find a significant S/N in DM models with a decay rate
fitting the positron excess as measured by PAMELA. This is the first
time that DM filaments are shown to be promising targets for indirect
detection of DM. On the other hand, the prospects for detectability of
annihilating DM in local extragalactic structures are less optimistic
even with extreme cross-sections. We make the DM density and density
squared maps publicly available online.