(a) Local velocity gradient magnitude map overlaid with the H₂ column density contours. (b) Herschel H₂ column density map overlaid with the normalized velocity vector maps. The arrows represent the estimated local velocity gradients which are rotated by 180° in order to better visualize the accretion directions in SE. The polarized angle of the Planck 353 GHz thermal dust emission has been rotated by 90° to trace the magnetic field direction which is indicated by the red line. In both panels, the contours correspond to H₂ column densities from 1 × 10²¹ cm⁻² to 1.6 × 10²² cm⁻² with a step of 3 × 10²¹ cm⁻², and the beam sizes for the H₂ column density and velocity gradient maps are shown as the gray and blue circles in the lower right corner. The three green plusesgive the positions of the three embedded YSOs, emb10, emb16, and Ser-emb 28 (Enoch et al. 2009), and the white crosses mark the positions of the seven dust cores (Enoch et al. 2007).