# Explaining the enhanced star formation rate of Jellyfish galaxies in galaxy clusters

## TL;DR

This paper investigates why JellyFish galaxies in clusters exhibit increased star formation rates by modeling the effects of intercluster medium pressure and magnetic shielding on gas content and star formation efficiency.

## Contribution

It introduces a model linking external pressure and magnetic shielding to enhanced star formation in JellyFish galaxies, aligning with observations.

## Key findings

- External pressure boosts star formation efficiency in JFGs.
- Magnetic fields shield clouds from evaporation, enabling star formation.
- JFGs are more likely if halo mass < 10^{11} M_sun, Mach number ~2, and inclination < 60°.

## Abstract

We study the recently observed JellyFish galaxies (JFGs), which are found to have their gas content ram-pressure stripped away in galaxy clusters. These galaxies are observed to have an enhanced star formation rate of about 0.2 dex compared with a control sample of the same stellar mass in their disks. We model the increase in the star formation efficiency as a function of interacluster medium pressure and parametrize the cold gas content of the galaxies as a function of cluster-centric distance. We show that regarding the external pressure as a positive feedback results in agreement with the observed distribution of enhanced star formation in the JFGs if clouds are shielded from evaporation by magnetic fields. Our results predict that satellites with halo mass $< 10^{11}M_{\odot}$ moving with Mach numbers $\mathcal{M}\approx2$, and inclination angles below 60 degrees, are more likely to be detected as JFGs.