Classification of gamma-ray targets for velocity-dependent and subhalo-boosted dark-matter annihilation

Abstract

Gamma-ray observations have long been used to constrain the properties of dark matter (DM), with a strong focus on weakly interacting massive particles annihilating through velocity-independent processes. However, in the absence of clear-cut observational evidence for the simplest candidates, the interest of the community in more complex DM scenarios involving a velocity-dependent cross-section has been growing steadily over the past few years. We present the first systematic study of velocity-dependent DM annihilation (in particular $p$-wave annihilation and Sommerfeld enhancement) in a variety of astrophysical objects, not only including the well-studied Milky Way dwarf satellite galaxies, but nearby dwarf irregular galaxies and local galaxy clusters as well. Particular attention is given to the interplay between velocity dependence and DM halo substructure. Uncertainties related to halo mass, phase-space and substructure modelling are also discussed in this velocity-dependent context. We show that, for $s$-wave annihilation, extremely large subhalo boost factors are to be expected, up to $10^{11}$ in clusters and up to $10^6-10^7$ in dwarf galaxies where subhalos are usually assumed not to play an important role. Boost factors for $p$-wave annihilation are smaller but can still reach $10^3$ in clusters. The angular extension of the DM signal is also significantly impacted, with e.g. the cluster typical emission radius increasing by a factor of order 10 in the $s$-wave case. We also compute the signal contrast of the objects in our sample with respect to annihilation happening in the Milky Way halo. Overall, we find that the hierarchy between the brightest considered targets depends on the specific details of the assumed particle-physics model.

52 pages, 10 figures. v3: minor changes, matches the published version

References in corpus (54)

• A Theory of Dark Matter
• The mass distribution and gravitational potential of the Milky Way
• Concentration, Spin and Shape of Dark Matter Haloes as a Function of the Cosmological Model: WMAP1, WMAP3 and WMAP5 results
• Cosmology and Astrophysics of Minimal Dark Matter
• Beasts of the Southern Wild: Discovery of nine Ultra Faint satellites in the vicinity of the Magellanic Clouds
• Searching for Dark Matter Annihilation in Recently Discovered Milky Way Satellites with Fermi-LAT
• Diffuse Radio Emission from Galaxy Clusters
• High-resolution mass models of dwarf galaxies from LITTLE THINGS
• A Catalog of Galaxy Clusters Observed by XMM-Newton
• Baryon effects on the internal structure of LCDM halos in the EAGLE simulations
• The Universal Rotation Curve of Spiral Galaxies. II The Dark Matter Distribution out to the Virial Radius
• Disruption of Dark Matter Substructure: Fact or Fiction?
• Generating Dark Matter Halo Merger Trees
• Statistics of X-ray observables for the cooling-core and non-cooling core galaxy clusters
• The galaxy cluster mass scale and its impact on cosmological constraints from the cluster population
• NGC 3741: dark halo profile from the most extended rotation curve
• Gamma Ray Signals from Dark Matter: Concepts, Status and Prospects
• Heavy Dark Matter Through the Higgs Portal
• Constraints on Dark Matter Annihilation in Clusters of Galaxies with the Fermi Large Area Telescope
• Dwarf galaxy annihilation and decay emission profiles for dark matter experiments
• Precise constraints on the dark matter content of Milky Way dwarf galaxies for gamma-ray experiments
• The Dark Matter Annihilation Signal from Galactic Substructure: Predictions for GLAST
• A New Faint Milky Way Satellite Discovered in the Pan-STARRS1 3 pi Survey
• TeV gamma-rays and the largest masses and annihilation cross sections of neutralino dark matter
• Indirect Dark Matter Detection from Dwarf Satellites: Joint Expectations from Astrophysics and Supersymmetry
• Dark-matter bound states from Feynman diagrams
• Galactic Substructure and Dark Matter Annihilation in the Milky Way Halo
• Spherical Jeans analysis for dark matter indirect detection in dwarf spheroidal galaxies - Impact of physical parameters and triaxiality
• Gamma rays from clusters of galaxies
• A New Milky Way Satellite Discovered In The Subaru/Hyper Suprime-Cam Survey
• The distribution function of dark matter in massive haloes
• Resolved Dwarf Galaxy Searches within ~5 Mpc with the Vera Rubin Observatory and Subaru Hyper Suprime-Cam
• Gamma Rays from Clusters and Groups of Galaxies: Cosmic Rays versus Dark Matter
• Analytical Approach to Subhaloes Population in Dark Matter Haloes
• HICOSMO - Cosmology with a complete sample of galaxy clusters: I. Data analysis, sample selection and luminosity-mass scaling-relation
• Indirect Dark Matter Detection Limits from the Ultra-Faint Milky Way Satellite Segue 1
• Modeling dark matter subhalos in a constrained galaxy: Global mass and boosted annihilation profiles
• Substructure Boosts to Dark Matter Annihilation from Sommerfeld Enhancement
• Dark Matter Indirect Signatures
• ATIC, PAMELA, HESS, Fermi and nearby Dark Matter subhalos
• gamma-rays from annihilating dark matter in galaxy clusters: stacking vs single source analysis
• Search for gamma-ray emission from $p$-wave dark matter annihilation in the Galactic Center
• Decaying dark matter: a stacking analysis of galaxy clusters to improve on current limits
• The Mass Function of Unprocessed Dark Matter Halos and Merger Tree Branching Rates
• Estimating the GeV Emission of Millisecond Pulsars in Dwarf Spheroidal Galaxies
• Effects of Velocity-Dependent Dark Matter Annihilation on the Energy Spectrum of the Extragalactic Gamma-ray Background
• HIFLUGCS: X-ray luminosity -- dynamical mass relation and its implications for mass calibrations with the SPIDERS and 4MOST surveys
• Detailed study of extended gamma-ray morphology in the vicinity of the Coma cluster with Fermi-LAT
• Disentangling cosmic-ray and dark-matter induced gamma-rays in galaxy clusters?
• $J$-factors for Velocity-dependent Dark Matter
• Velocity-dependent annihilation radiation from dark matter subhalos in cosmological simulations
• Statistics of Dark Matter Substructure: II. Comparison of Model with Simulation Results
• Constraining Dark Matter Microphysics with the Annihilation Signal from Subhalos
• Tidal stripping of dark matter subhalos by baryons from analytical perspectives: disk shocking and encounters with stars

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• Investigating the effect of Milky Way dwarf spheroidal galaxies extension on dark matter searches with Fermi-LAT data
• Prospects for $\gamma$-ray observations of the Perseus galaxy cluster with the Cherenkov Telescope Array
• Searching for velocity-dependent dark matter annihilation signals from extragalactic halos
• Velocity-dependent J-factors for Milky Way dwarf spheroidal analogues in cosmological simulations
• Analytical insight into dark matter subhalo boost factors for Sommerfeld-enhanced $s$- and $p$-wave $\gamma$-ray signals