Positions of the 57 dense cores (FWHM Gaussian ellipses) identified in the X-shaped nebula region overlaid on the Herschel high-resolution (18.2″) column density map. Magenta ellipses, blue ellipses, black ellipses, and green stars mark the 24 unbound starless cores, the 11 candidate prestellar cores, the 20 robust prestellar cores, and the two protostellar cores, respectively (see Sect. 3.3). The skeleton of the filament network extracted in Sect. 3.2 is shown by white curves. The thirteen 5′ × 5′ fields covered by the SMT CO observations are marked as black boxes.