Detecting the disruption of dark-matter halos with stellar streams

TL;DR

This paper investigates how stellar streams in the Milky Way can reveal the presence and disruption of dark-matter subhalos, providing insights into the halo's structure and dark matter properties.

Contribution

It introduces analytical and N-body methods to detect disrupted dark-matter subhalos via their effects on stellar streams, advancing understanding of halo lumpiness.

Findings

Disrupted subhalos can be identified as low-concentration features in stellar streams.

The method constrains dark-matter halo substructure and subhalo orbits.

Implications for dark-matter detection and halo formation theories.

Abstract

Narrow stellar streams in the Milky Way halo are uniquely sensitive to dark-matter subhalos, but many of these subhalos may be tidally disrupted. I calculate the interaction between stellar and dark-matter streams using analytical and $N$-body calculations, showing that disrupting objects can be detected as low-concentration subhalos. Through this effect, we can constrain the lumpiness of the halo as well as the orbit and present position of individual dark-matter streams. This will have profound implications for the formation of halos and for direct and indirect-detection dark-matter searches.