H₂O column density retrieved on nine VIRTIS-M images, acquired from 11 to 13 April 2015 at rotational phases φ. Image details are provided in Table A.1, as identified with the italic character. In the images a), h), i), emissions are located in the southern hemisphere. Intensities are provided in terms of 10²⁰ molecules m^-2. The simulation on the left with respect to the water maps shows the comet’s x,y,z axes, and the Sun direction for the images a), d), and g). The square is the full (3.6° × 3.6°) VIRTIS-M field of view. It corresponds to the images horizontal width, while the vertical size depends on the number of consecutive lines acquired for each image.