Dispersion coordinates field image_Mrk 421_obsid_20942 Sky field image_Mrk 421_obsid_20942 Source region detail images_Mrk 421_obsid_20942 Light curve_Mrk 421_obsid_20942 Counts Spectrum (1)_Mrk 421_obsid_20942 Counts Spectrum (2)_Mrk 421_obsid_20942 Counts Spectrum (3)_Mrk 421_obsid_20942 Counts Spectrum (4)_Mrk 421_obsid_20942 Flux Preview_Mrk 421_obsid_20942