Reheating neutron stars with the annihilation of self-interacting dark matter

TL;DR

This paper investigates how self-interacting dark matter captured by neutron stars can lead to reheating through annihilation, producing detectable infrared signals and offering a new way to probe dark matter properties.

Contribution

It introduces the concept that dark matter self-interactions can enhance neutron star heating via annihilation, providing a novel observational signature.

Findings

Self-interacting dark matter increases neutron star surface temperature to hundreds of Kelvin.

Reheated neutron stars could be detected by future infrared telescopes.

The process offers a complementary method to direct dark matter detection.

Abstract

Compact stellar objects such as neutron stars (NS) are ideal places for capturing dark matter (DM) particles. We study the effect of self-interacting DM (SIDM) captured by nearby NS that can reheat it to an appreciated surface temperature through absorbing the energy released due to DM annihilation. When DM-nucleon cross section $\sigma_{\chi n}$ is small enough, DM self-interaction will take over the capture process and make the number of captured DM particles increased as well as the DM annihilation rate. The corresponding NS surface temperature resulted from DM self-interaction is about hundreds of Kelvin and is potentially detectable by the future infrared telescopes. Such observations could act as the complementary probe on DM properties to the current DM direct searches.