The supersonic nature of jellyfish galaxies

Abstract

All gas-rich galaxies in cluster environments are expected to experience ram-pressure stripping from the intra-cluster medium. However, only a fraction of these develop ongoing star-formation in their stripped tail, becoming the so-called ``jellyfish'' galaxies. In this work we provide observational evidence that magnetic fields can signal differences in the extraplanar star formation and explore what are the physical conditions that lead to the formation of a jellyfish galaxy. We first focus on JO147, a jellyfish galaxy that features weak star formation activity in its tail. Using MeerKAT radio continuum observations, we discover polarized emission only in a small fraction of its tail, with an average fraction of $10\%$, and a low Mach number $\mathcal{M}=1.3-1.6$, which suggests a possible association between magnetic field draping, shock-compression of the gas, and extraplanar star formation activity. Then, we test this scenario in a sample of 17 jellyfish galaxies from the GASP project. We combine dynamical models for their orbits within the host clusters with realistic cluster temperature profiles to infer their Mach number, and we find a positive correlation between it and the star formation activity in their tail. We conclude that supersonic motion is a necessary condition for triggering star formation in the stripped tails of jellyfish galaxies. Our findings provide empirical evidence that the critical factor preventing the stripped gas evaporation is the shock compression induced by the supersonic motion through the cluster. This process likely enhances the magnetic field surrounding the galaxy and the properties of the stripped material.

Accepted for publication on A&A

References in corpus (40)

• Intracluster Medium Entropy Profiles for a Chandra Archival Sample of Galaxy Clusters
• Ram Pressure Stripping in High-Density Environments
• SoFiA: a flexible source finder for 3D spectral line data
• Draping of Cluster Magnetic Fields over Bullets and Bubbles -- Morphology and Dynamic Effects
• Magnetized Gas Clouds can Survive Acceleration by a Hot Wind
• A statistically-selected Chandra sample of 20 galaxy clusters -- I. Temperature and cooling time profiles
• SoFiA 2 -- An automated, parallel HI source finding pipeline for the WALLABY survey
• Interaction of a cold cloud with a hot wind: the regimes of cloud growth and destruction and the impact of magnetic fields
• GASP XXIII: A jellyfish galaxy as an astrophysical laboratory of the baryonic cycle
• The concentration-mass relation of clusters of galaxies from the OmegaWINGS survey
• GASP XXI. Star formation rates in the tails of galaxies undergoing ram-pressure stripping
• A cluster in a crowded environment: XMM-Newton and Chandra observations of A3558
• From blue star-forming to red passive: galaxies in transition in different environments
• Radio footprints of a minor merger in the Shapley Supercluster: From supercluster down to galactic scales
• Highly ordered magnetic fields in the tail of the jellyfish galaxy JO206
• Jellyfish galaxies with the IllustrisTNG simulations -- When, where, and for how long does ram pressure stripping of cold gas occur?
• A universal correlation between warm and hot gas in the stripped tails of cluster galaxies
• Shapley Supercluster Survey (ShaSS): Galaxy Evolution from Filaments to Cluster Cores
• GASP XXXVIII: The LOFAR-MeerKAT-VLA view on the non-thermal side of a jellyfish galaxy
• A New Method to Constrain the Appearance and Disappearance of Observed Jellyfish Galaxy Tails
• Linking a universal gas density profile to the core-excised X-ray luminosity in galaxy clusters up to z ~ 1.1
• Radio continuum tails in ram pressure-stripped spiral galaxies: experimenting with a semi-empirical model in Abell 2255
• Simulations of the polarized radio sky and predictions on the confusion limit in polarization for future radio surveys
• Introducing PT-REX, the Point-to-point TRend EXtractor
• The MUSE view of ram pressure stripped galaxies in clusters: the GASP sample
• Constraining the duration of ram pressure stripping features in the optical from the direction of jellyfish galaxy tails
• The MeerKAT Fornax Survey IV. A close look at the cluster physics through the densest rotation measure grid
• The MeerKAT Fornax Survey. III. Ram-pressure stripping of the tidally interacting galaxy NGC 1427A in the Fornax cluster
• Turbulence in the Tail of a Jellyfish Galaxy
• HST viewing of spectacular star-forming trails behind ESO 137-001
• Unveiling the interplay between the GASP jellyfish galaxy JO194 and its environment with Chandra
• The magnetised and thermally unstable tails of jellyfish galaxies
• The Halo Mass-Temperature Relation for Clusters, Groups, and Galaxies
• Cosmic dance in the Shapley Concentration Core II. The uGMRT-MeerKAT view of filaments in the brightest cluster galaxies and tailed radio galaxies in the A3528 cluster complex
• Star formation at different stages of ram-pressure stripping as observed through far-ultraviolet imaging of 13 GASP galaxies
• A 100 kpc Ram Pressure Tail Trailing the Group Galaxy NGC 2276
• Comparing the interstellar and circumgalactic origin of gas in the tails of jellyfish galaxies
• ESO 137-001 -- a jellyfish galaxy model
• The role of magnetic fields in ram pressure stripping of satellite galaxies in the circumgalactic medium around massive galaxies
• A Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE). XIX. The discovery of a spectacular 230 kpc Halpha tail following NGC 4569 in the Virgo cluster