Flashlights: Properties of Highly Magnified Images Near Cluster Critical Curves in the Presence of Dark Matter Subhalos

Understand

Dark matter subhalos with extended profiles and density cores, and globular stars clusters of mass $10^6-10^8 M_\odot$, that live near the critical curves in galaxy cluster lenses can potentially be detected through their lensing magnification of stars in background galaxies.

• In this work we study the effect such subhalos have on lensed images, and compare to the case of more well studied microlensing by stars and black holes near critical curves.
• We find that the cluster density gradient and the extended mass distribution of subhalos are important in determining image properties.
• Both lead to an asymmetry between the image properties on the positive and negative parity sides of the cluster that is more pronounced than in the case of microlensing.