Two-dimensional images of the most relevant lines detected at the redshift of the arclet. From left to right, the Lyα, [O III]λ5007, Hα and the sum of the Balmer lines, Hγ, Hβ, and Hα. The first and second rows show the same images, derived after averaging three slices at the wavelength position of the lines. In the second row, the knots are labeled: the black circles highlight the components B1,2 and the ellipse marks the position of source 1. The black curve outlines the critical line of the customized lens model.