LoTSS Jellyfish Galaxies III. The first identification of jellyfish\n galaxies in the Perseus cluster

Abstract

In this paper we report the first identification of jellyfish galaxies in the\nPerseus cluster (Abell 426). We identified four jellyfish galaxies (LEDA\n2191078, MCG +07-07-070, UGC 2654, UGC 2665) within the central $2^\\circ \\times\n2^\\circ$ ($2.6\\,\\mathrm{Mpc} \\times 2.6\\,\\mathrm{Mpc}$) of Perseus based on the\npresence of one-sided radio continuum tails that were detected at\n$144\\,\\mathrm{MHz}$ by the LOw Frequency ARray (LOFAR). The observed radio\ntails, as well as the orientation of morphological features in the rest-frame\noptical, are consistent with these four galaxies being impacted by ram pressure\nstripping as they orbit through the Perseus intracluster medium. By combining\nthe LOFAR imaging at 144 MHz with 344 MHz imaging from the Karl G. Jansky Very\nLarge Array, we derived spectral indices for the disks and the stripped tails\nof these jellyfish galaxies. We show that the spectral indices over the galaxy\ndisks are quite flat, while the indices of the stripped tails are substantially\nsteeper. We also identified a number of compact $\\mathrm{H\\alpha + [NII]}$\nsources with narrowband imaging from the Isaac Newton Telescope. These sources\nare brighter along the leading side of the galaxy (i.e., opposite to the\ndirection of the stripped tail), which is consistent with ram pressure induced\nstar formation. Lastly, consistent with previous works in other clusters, we\nfind that these jellyfish galaxies show enhanced radio luminosities for their\nobserved star formation rates. Given the small distance to the Perseus cluster\n($D \\sim 70\\,\\mathrm{Mpc}$, $1'' \\simeq 340\\,\\mathrm{pc}$), these galaxies are\nexcellent candidates for multiwavelength follow-up observations to probe the\nimpact of ram pressure stripping on galaxy star formation at subkiloparsec\nscales.\n