GASP XXXVII: The Most Extreme Jellyfish Galaxies Compared with Other Disk Galaxies in Clusters, an H i Study

Abstract

We present the results of a Very Large Array H i imaging survey aimed at understanding why some galaxies develop long extraplanar Hα tails, becoming extreme jellyfish galaxies. The observations are centered on five extreme jellyfish galaxies optically selected from the WINGS and OMEGAWINGS surveys and confirmed to have long Hα tails through MUSE observations. Each galaxy is located in a different cluster. In the observations, there are in total 88 other spiral galaxies within the field of view (40′ × 40′) and observed bandwidth (6500 km s−1). We detect 13 of these 88 spirals, plus one uncataloged spiral, with H i masses ranging from 1 to 7 × 109 M ⊙. Many of these detections have extended H i disks, two show direct evidence for ram pressure stripping, and others are possibly affected by tidal forces and/or ram pressure stripping. We stack the 75 nondetected spiral galaxies and find an average H i mass of 1.9 × 108 M ⊙, which, given their average stellar mass, implies that they are very H i deficient. Comparing the extreme jellyfish galaxies to the other disk galaxies, we find that they are at smaller projected distance from the cluster center, and have a higher stellar mass and higher relative velocity than all other H i detections and most nondetections. We conclude that the high stellar mass allows extreme jellyfish galaxies to fall deeply into the cluster before being stripped, and the surrounding ICM pressure gives rise to their spectacular star-forming tails.

Environmental cluster effects and galaxy evolution: The H i properties of the Abell clusters A85/A496/A2670

“…As a matter of fact, the central regions of A85 could be an extreme case even compared with Coma, where a number of gas deficient spirals are still detected within 1 Mpc, with similar Hi mass limit detection than the present work (Bravo-Alfaro et al 2000;Healy et al 2021;Molnár et al 2022). In A85 the only Hi projected close to the center is the high-speed infalling jellyfish JO201, which shows signs of strong ram pressure stripping (Ramatsoku et al 2020;Luber et al 2022).…”

“…The gas rich galaxies are projected 1.5−3.0 Mpc away from the cluster center, while a remarkable absence of Hi detections at lower radius suggests the presence of a harsh environment. This fact is independently supported by the presence of strongly perturbed galaxies (Venkatapathy et al 2017;Ramatsoku et al 2020;Luber et al 2022).…”

“…In order to properly display the three systems in a single plot we normalize the galaxy cluster-centric distance by the corresponding R200. The relative velocities are normalized by the corresponding cluster velocity dispersion σ cl (see Luber et al 2022).…”

Walk on the Low Side: LOFAR Explores the Low-frequency Radio Emission of GASP Jellyfish Galaxies

“…A number of jellyfish galaxies are also found to show extraplanar, nonthermal radio emission (e.g., Gavazzi 1978;Gavazzi & Jaffe 1986;Gavazzi et al 1995;Gavazzi & Boselli 1999;Vollmer et al 2013;Poggianti et al 2019a;Chen et al 2020;Ignesti et al 2020;Roberts et al 2021bRoberts et al , 2021aMüller et al 2021;Ignesti et al 2022;Luber et al 2022;Roberts et al 2022). In general, radio continuum emission in spiral galaxies is composed of thermal emission from ∼10 4 K plasma in HII regions produced via thermal bremsstrahlung, and the nonthermal synchrotron emission of relativistic cosmic ray electrons (CRe), which are accelerated by supernovae shocks, reaching energies of a few GeV (e.g., see Condon 1992 for a review).…”

GASP XXXIX: MeerKAT hunts Jellyfish in A2626

“…Together with PP, UMa, and A2626 galaxies, we have also plotted the results from the Arecibo Legacy Fast ALFA-Sloan Digital Sky Survey (ALFALFA-SDSS) galaxy sample of field galaxies with errorbars from Maddox et al (2015), which spans a large range in stellar and H i masses. All five galaxies that are under the influence of RPS (JO201, JO204, JO206, JW100, and JW103) have relatively low H i masses for their stellar masses when compared to the reference sample galaxies (also found by Luber et al 2022). Especially, when compared with the ALFALFA field galaxies, all five JFGs are almost 1 dex below the typical H i masses of the galaxies of similar stellar masses.…”