2025A&A...699A.188W

Jellyfish galaxies display long tails of gas that was removed from their stellar disks through a process known as ram-pressure stripping. These objects represent a fast transition phase between star-forming and quiescent galaxies and are often regarded as the progenitors of cluster post-starburst galaxies. We explore the evolution of these systems at 0.29<z<0.5 by identifying quenched regions in their stellar disks. To do this, we introduce a new spectral classification method based on convolutional neural networks. Signatures of ongoing quenching are detected in a relevant fraction of the stellar disk in 6 out of 18 jellyfish galaxies. When the objects with the longest tails are considered alone, however, the detection rate of quenched regions is much higher (6 out of 8 galaxies). Quenched regions are typically organized in arc-shaped regions and are concentrated at the leading edge of the disk (opposite to the tail). The global star formation rates (SFRs) of quenching jellyfish galaxies that still remain partially star-forming are systematically higher than those of other jellyfish galaxies. The SFR enhancement in jellyfish galaxies that undergo quenching is concentrated in their central regions (high stellar mass density $ \Sigma _{M_\star } $), while for $ \Sigma _{M_\star } < 10^{7.5}\,\mathrm {M_\odot /kpc^2} $, they follow the same $ \Sigma _{M_\star }{-}\Sigma _\mathrm {SFR} $ relation as other jellyfish galaxies. Our results indicate a scenario in which gas is quickly stripped from the outskirts of the stellar disks while star formation is boosted toward the central regions of galaxies. This might lead to the outside-in quenching patterns that are observed in cluster post-starburst galaxies.