Gravitational Lensing as a Probe of Cold Dark Matter Subhalos
Figure 2
Macrolensed and singly imaged sources. (a) The sightline towards a distant light source passes through many dark matter halos with subhalos, but too far from the dense galaxies in the centres of halos for macrolensing to occur. A subhalo in one of these halos happens to intersect the line of sight, thereby potentially producing millilensing effects in a singly imaged light source. (b) One of the halos happens to lie almost exactly on the line of sight, thereby splitting the background light source into separate macroimages. Furthermore, one of the subhalos in the main lens lies on the sightline towards one of the macroimages, thereby producing millilensing effects in this macroimage.
