Causal relationship between enhanced localized heating of the chromosphere and coronal rain flows in region B. (a) AIA 304 Å image. At its right bottom corner, an NVST Hα image shows the enhanced localized heating of the chromosphere in a sunspot. (b) Space-time diagram of AIA 304 Å intensity for the “Slit A” trajectory shown in panel a. (c) Space-time diagram of NVST Hα intensity for the “Slit B” trajectory shown in the Hα image in panel a. The yellow vertical dashed lines in panels b and c represent the start time (03:31 UT) of the bright dot appearance. The yellow plus signs in panels a and b denote the position of the bright dot.