Multiwavelength analysis of dark matter annihilation and RX-DMFIT

Abstract

Dark matter (DM) particles are predicted by several well motivated models to yield Standard Model particles through self-annihilation that can potentially be detected by astrophysical observations. In particular, the production of charged particles from DM annihilation in astrophysical systems that contain magnetic fields yields radio emission through synchrotron radiation and X-ray emission through inverse Compton scattering of ambient photons. We introduce RX-DMFIT, a tool used for calculating the expected secondary emission from DM annihilation. RX-DMFIT includes a wide range of customizable astrophysical and particle parameters and incorporates important astrophysics including the diffusion of charged particles, relevant radiative energy losses, and magnetic field modelling. We demonstrate the use and versatility of RX-DMFIT by analyzing the potential radio and X-ray signals for a variety of DM particle models and astrophysical environments including galaxy clusters, dwarf spheroidal galaxies and normal galaxies. We then apply RX-DMFIT to a concrete example using Segue I radio data to place constraints for a range of assumed DM annihilation channels. For WIMP models with M χ ≤ 100 GeV and assuming weak diffusion, we find that the the leptonic µ + µ − and τ + τ − final states provide the strongest constraints, placing limits on the DM particle cross-section well below the thermal relic cross-section, while even for the bb channel we find limits close to the thermal relic cross-section. Our analysis shows that radio emission provides a highly competitive avenue for dark matter searches.

Constraints on dark matter annihilation in dwarf spheroidal galaxies from low frequency radio observations

“…This leads to the largest possible values of flux that one could get from the current analysis. Stronger magnetic fields and lower values of D 0 are disfavoured by already existing observations [3,18,19,22,24]. DSph's which have larger D 0 and smaller magnetic fields (i.e.…”

Heavy dark matter particle annihilation in dwarf spheroidal galaxies: Radio signals at the SKA telescope

“…m χ is the DM mass and ρ χ (r) is the DM density profile in the dSph as a function of radial distance r from the centre of the dSph. For our analysis we have taken Draco 1 dSph assuming an Navarro-Frenk-White (NFW) profile 2 [47], yielding with ρ s = 1.4 GeV.cm −3 and r s = 1.0 kpc [40,43]. Figure 1 essentially shows the e + e − energy distributions for four different annihilation channels, for two DM masses, namely, 300 GeV and 5 T eV .…”

“…where D(E) is the diffusion parameter which can be parameterised in terms of diffusion coefficient (D 0 ) as D(E) = D 0 E 0.3 [33,40,43]. Choice of D 0 like D 0 = 3 × 10 28 cm 2 s −1 is conservative for dSph like Draco.…”

“…The spectrum as well as the dynamics of the particle physics scenario, along with the DM profile in a dSph, is responsible for DM annihilation as well as the subsequent cascades leading to electron-positron pairs. The electron(positron) energy distribution at the initial level is also the determined by the above factors [39][40][41]. However, they subsequently pass through the interstellar medium (ISM) of the galaxy, facing several additional effects.…”

“…However, they subsequently pass through the interstellar medium (ISM) of the galaxy, facing several additional effects. These include diffusion as well as electromagnetic energy loss in various forms, including Inverse Compton effect, Synchrotron loss, Coulomb effect and Bremsstrahlung effect [39,40,42,43]. Besides, the galactic magnetic field is operative all along.…”