Velocity-dependent annihilation radiation from dark matter subhalos in cosmological simulations

Abstract

We use the suite of Milky Way-like galaxies in the Auriga simulations to determine the contribution to annihilation radiation from dark matter subhalos in three velocity-dependent dark matter annihilation models: Sommerfeld, p-wave, and d-wave models. We compare these to the corresponding distribution in the velocity-independent s-wave annihilation model. For both the hydrodynamical and dark-matter-only simulations, only in the case of the Sommerfeld-enhanced annihilation does the total annihilation flux from subhalos exceed the total annihilation flux from the smooth halo component within the virial radius of the halo. Progressing from Sommerfeld to the s, p, and d-wave models, the contribution from the smooth component of the halo becomes more dominant, implying that for the p-wave and d-wave models the smooth component is by far the dominant contribution to the radiation. Comparing to the Galactic center excess observed by Fermi-LAT, for all simulated halos the emission is dominated by the smooth halo contribution. However, it is possible that for Sommerfeld models, extrapolation down to mass scales below the current resolution limit of the simulation would imply a non-negligible contribution to the gamma-ray emission from the Galactic Center region.

18 pages, 8 figures, 1 table

References in corpus (15)

• The EAGLE project: Simulating the evolution and assembly of galaxies and their environments
• The EAGLE simulations of galaxy formation: calibration of subgrid physics and model variations
• The Auriga Project: the properties and formation mechanisms of disc galaxies across cosmic time
• The redshift dependence of the structure of massive LCDM halos
• Dark matter and cosmic structure
• A blueprint for detecting supersymmetric dark matter in the Galactic halo
• Heavy Dark Matter Through the Higgs Portal
• Fermi Large Area Telescope observations of Local Group galaxies: Detection of M31 and search for M33
• The characteristics of the Galactic center excess measured with 11 years of Fermi-LAT data
• Dark Matter Interpretation of the Fermi-LAT Observations Toward the Outer Halo of M31
• Amplified J-factors in the Galactic Center for velocity-dependent darkmatter annihilation in FIRE simulations
• Baryonic effects on the detectability of annihilation radiation from dark matter subhaloes around the Milky Way
• Velocity-dependent J-factors for annihilation radiation from cosmological simulations
• Dark matter annihilation and the Galactic Centre Excess
• Optimal observing strategies for velocity-suppressed dark matter annihilation

Cited by in corpus (3)

• Classification of gamma-ray targets for velocity-dependent and subhalo-boosted dark-matter annihilation
• Searching for velocity-dependent dark matter annihilation signals from extragalactic halos
• Velocity-dependent J-factors for Milky Way dwarf spheroidal analogues in cosmological simulations