Spatial association of the RHESSI X-ray sources with the ribbon structure. Panel a) shows the only time at which a non-thermal source (20–50 keV) was near the NR structure. Panel b) shows that a short time later, the higher energy source are no longer located near the ribbon (this image uses 20–25 keV and 15–20 keV as the higher energy passbands contained significant noise at these times). Panel c) shows the 6–9 keV compact sources that are positioned near the NR. Dotted lines show the IRIS slit positions.