Figure 41

Figure 41: (a) The four images of the quasar Q2237+030 (known as the Einstein cross), gravitationally lensed by an isolated bulge-disk galaxy known as Huchra’s lens [197]. © ESA’s faint object camera on HST. (b) The empty squares denote the four observed positions of the images, and the filled square denotes the MOND-fit unique position of the source [419]. The critical curves for which M −1 = 0 in the lens plane are displayed in black, and their corresponding caustics in the source plane in red. Image reproduced by permission from [419].