English

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

Astrophysics of Galaxies 2019-04-24 v1

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 <1011M< 10^{11}M_{\odot} moving with Mach numbers M2\mathcal{M}\approx2, and inclination angles below 60 degrees, are more likely to be detected as JFGs.

Keywords

Cite

@article{arxiv.1904.05900,
  title  = {Explaining the enhanced star formation rate of Jellyfish galaxies in galaxy clusters},
  author = {Mohammadtaher Safarzadeh and Abraham Loeb},
  journal= {arXiv preprint arXiv:1904.05900},
  year   = {2019}
}

Comments

accepted for publication in MNRAS Letters