Dispersion coordinates field image_H 1821+643_obsid_22469 Sky field image_H 1821+643_obsid_22469 Source region detail images_H 1821+643_obsid_22469 Light curve_H 1821+643_obsid_22469 Counts Spectrum (1)_H 1821+643_obsid_22469 Counts Spectrum (2)_H 1821+643_obsid_22469 Counts Spectrum (3)_H 1821+643_obsid_22469 Counts Spectrum (4)_H 1821+643_obsid_22469 Flux Preview_H 1821+643_obsid_22469