Set of images describing the procedure used to determine the ϵ correction factor (or JvM-factor) based on Czekala et al. (2021). The plots refer to the 7M+TM2+TM1 continuum data of the ALMAGAL field 644284 (also labelled AG285.2633–0.0501 in Molinari et al. 2025). Top panel: normalized, elliptically averaged profile of the dirty beam (or PSF, in orange) and clean beam (black dashed line). The vertical dotted line marks the “zero-crossing” point of the dirty beam. Note that the PSF range of the elliptically averaged dirty beam is considered to determine the crossing point, thus resulting in a more conservative correction factor. Second and third panels: differential and cumulative volumes of the dirty and clean beams (see Czekala et al. 2021 for details in the calculation). Bottom panel: ratio of the clean and dirty beam volumes. The value of this ratio at the distance of the dirty-beam zerocrossing point provides the ϵ (or JvM) correction factor (0.138 in this example).