Remnants of dark matter clumps

TL;DR

This paper models the tidal destruction of dark matter clumps in the Galactic halo, showing that dense core remnants can survive and significantly contribute to annihilation signals despite tidal forces.

Contribution

It provides a detailed calculation of the survival probability of dark matter clump remnants and their impact on annihilation signals, considering core size and minimal mass uncertainties.

Findings

A substantial fraction of dark matter clump remnants survive tidal destruction.

Dense core remnants dominate the annihilation signal in the Galaxy.

Surviving remnants extend the mass spectrum down to the core mass of small clumps.

Abstract

What happened to the central cores of tidally destructed dark matter clumps in the Galactic halo? We calculate the probability of surviving of the remnants of dark matter clumps in the Galaxy by modelling the tidal destruction of the small-scale clumps. It is demonstrated that a substantial fraction of clump remnants may survive through the tidal destruction during the lifetime of the Galaxy if the radius of a core is rather small. The resulting mass spectrum of survived clumps is extended down to the mass of the core of the cosmologically produced clumps with a minimal mass. Since the annihilation signal is dominated by the dense part of the core, destruction of the outer part of the clump affects the annihilation rate relatively weakly and the survived dense remnants of tidally destructed clumps provide a large contribution to the annihilation signal in the Galaxy. The uncertainties in minimal clump mass resulting from the uncertainties in neutralino models are discussed.