Magnetic field maps (in grey scale) from SDO/HMI of a part of the active region 11158, on February 15, 2011, at 01:48:00 UT (left) and 02:00:00 UT (right). The orange and blue contours represent the positive and negative vertical electric current densities, respectively, with amplitude >100 mA/m². The green, cyan, and yellow contours are the X-ray emissions (from RHESSI) at 12−25 keV, 25−50 keV, and 50−100 keV, respectively, integrated between a) 01:49:00 and 01:49:16; b) 01:51:00 and 01:51:16; c) 01:52:42 and 01:52:58; d) 01:55:02 and 01:55:18; and e) 01:55:22 and 01:55:38 UT. X-rays have been imaged with the algorithm CLEAN, using collimators 2, 3, 4, 5, 6, 7, 8, and 9. The contours correspond to 60, 70, 80, and 90% of the maximum for the X-ray emissions.