Performances of the LTB in IRIS SJI images. (a) SJI 1400 image overlaid with contours to denote the brightness kernels. The raster numbers 5, 6, and 7 are plotted. (b) Space-time brightness map obtained along the dotted line PQ in panel a. The intensity is on an inverse scale. (c)–(k) Intensity distribution in the instance marked by the short solid line in panel b. The black lines in panel a denote the position of the IRIS slits.