Herschel H₂ column density image. The white rectangle indicates the filament that collided with the dense core in our CFC model. The white box with the coordinates is the observation box. The circle at the bottom-left corner represents the beam size of the Herschel map. The small circle near the centre is the position of the protostar. The colour represents the H₂ column density in cm⁻². The green contours are drawn at the H₂ column density levels of 5 ×10²¹, 2 ×10²², 3 ×10²², 5 ×10²², and 1 ×10²³ cm⁻³.