Chromospheric response and magnetograms. AIA 1600 Å images (panels a, b), HMI LOS magnetogram (c) and 1600 Å difference image (d) for October 11, 2021. Green contours show the STIX image in the 16−28 keV energy range, red in 4−8 keV (30, 60, 90% of the maximum intensity). The HMI image is scaled from −700 to +700 G. Units are given in arcseconds. Integration times are 19:23:21–19:24:36 UT for the non-thermal and 19:24:51–19:26:31 UT for the thermal image, respectively.