Solar wind bremsstrahlung off DM in our solar system

TL;DR

This paper explores the potential for solar wind particles to emit bremsstrahlung photons through interactions with dark matter in the solar system, predicting possible observable signals at millimeter or centimeter wavelengths.

Contribution

It introduces a novel calculation of bremsstrahlung emission from solar wind-dark matter interactions, using Monte Carlo simulations to estimate detectable photon rates.

Findings

Photon emission rates are generally very small.

Potential observability at millimeter and centimeter wavelengths.

Interaction signatures could inform dark matter properties.

Abstract

We consider the possibility that the solar wind emits photons via bremsstrahlung when colliding with Dark Matter (DM) particles within the solar system. To this effect, we calculate the bremsstrahlung spectrum a proton would emit when colliding with a neutral spin-1/2 particle through the exchange of a scalar neutral particle. We assume a speed of 600 km/sec for the solar wind and assume that the speed of the dark matter halo is due to the motion of the sun through the galaxy, which we take as 300 km/sec. We assume a DM density of 0.3 GeV/cm^3 and a solar wind composed primarily of protons with a total rate of ejection mass set at 10^9kg/sec. We use a Monte Carlo technique to let this interaction take place within the solar system and calculate the photon rate an observer would detect on Earth or at the edge of the solar system as a function of photon energy. We find that the rates are in general very small but could be observable in some scenarios at wavelengths in the mm or cm range.