Spatial extension of dark subhalos as seen by Fermi-LAT and implications for WIMP constraints
arXiv:2204.00267 · doi:10.1103/PhysRevD.105.083006
Abstract
Spatial extension has been hailed as a "smoking gun" in the gamma-ray search of dark galactic subhalos, which would appear as unidentified sources for gamma-ray telescopes. In this work, we study the sensitivity of the Fermi-LAT to extended subhalos using simulated data based on a realistic sky model. We simulate spatial templates for a set of representative subhalos, whose parameters were derived from our previous work with N-body cosmological simulation data. We find that detecting an extended subhalo and finding an unequivocal signal of angular extension requires, respectively, a flux 2 to 10 times larger than in the case of a point-like source. By studying a large grid of models, where parameters such as the WIMP mass, annihilation channel or subhalo model are varied significantly, we obtain the response of the LAT as a function of the product of annihilation cross section times the J-factor. Indeed, we show that spatial extension can be used as an additional filter to reject subhalos candidates among the pool of unidentified LAT sources, as well as a "smoking gun" for positive identification. For instance, typical angular extensions of a few tenths of degree are expected for the considered scenarios. Finally, we also study the impact of the obtained LAT sensitivity to such extended subhalos on the achievable dark matter constraints, which are a few times less constraining than comparable point-source limits.
21 pages, 17 figures, 3 tables. Matches the PRD accepted version
References in corpus (20)
- The NumPy array: a structure for efficient numerical computation
- Searching for Dark Matter Annihilation in Recently Discovered Milky Way Satellites with Fermi-LAT
- Disruption of Dark Matter Substructure: Fact or Fiction?
- Search for dark matter annihilations towards the inner Galactic halo from 10 years of observations with H.E.S.S
- A mass-dependent density profile for dark matter haloes including the influence of galaxy formation
- Dark Matter Substructure in Numerical Simulations: A Tale of Discreteness Noise, Runaway Instabilities, and Artificial Disruption
- Review of LHC Dark Matter Searches
- A blueprint for detecting supersymmetric dark matter in the Galactic halo
- Dark Matter: A Primer
- Constraints on Dark Matter Annihilation in Clusters of Galaxies with the Fermi Large Area Telescope
- Dark matter subhalos and the dwarf satellites of the Milky Way
- The moment of truth for WIMP Dark Matter
- Fitting the Gamma-Ray Spectrum from Dark Matter with DMFIT: GLAST and the Galactic Center Region
- Observations of M31 and M33 with the Fermi Large Area Telescope: a galactic center excess in Andromeda?
- Indirect dark matter searches in Gamma- and Cosmic Rays
- Modeling dark matter subhalos in a constrained galaxy: Global mass and boosted annihilation profiles
- DASH: a library of dynamical subhalo evolution
- Unidentified Gamma-ray Sources as Targets for Indirect Dark Matter Detection with the Fermi-Large Area Telescope
- Estimating the GeV Emission of Millisecond Pulsars in Dwarf Spheroidal Galaxies
- Spectral and spatial analysis of the dark matter subhalo candidates among Fermi Large Area Telescope unidentified sources