Sky region around PSR J2021+4026 (illustrated by the black cross) as seen by the XMM-Newton PN camera in small-window mode. This image is binned, color-coded, vignetting-corrected, and adaptively smoothed in the same way as Figure 1. Soft emission around the pulsar can be clearly seen. A cocoon-like feature around PSR J2021+4026 is highlighted by a solid line ellipse, which is adopted as the extraction region for the spectra from all EPIC cameras. The dashed circle shows the background region used in the remnant analysis. The bright red spot at the bottom is an artifact at edge of the window. Top is north and left is east.