Cosmological jellyfish

Galaxies and Cosmology Theory Team at the Max Planck Institute for Astronomy

The "Cosmological Jellyfish" project is run by members of the Galaxy and Cosmology Theory group at the Max-Planck-Institute for Astronomy (MPIA), headed by Annalisa Pillepich and in collaboration with the IllustrisTNG team. Broadly, our team endeavours to understand how galaxies evolve in different environments, i.e. in isolation vs. as part of a group of a few galaxies vs. as satellites of massive galaxy clusters containing thousands of galaxies. Our work is based on the results of the IllustrisTNG suite of cosmological simulations, which were developed by a collaboration of several astronomers, including members from our own group.

The project team includes:

Annalisa Pillepich (Group Leader)
Elad Zinger (Postdoc)
Kiyun Yun (PhD Student)
Gandhali Joshi (Postdoc)
Martina Donnari (Postdoc)

Markus Pössel (Head of the MPIA outreach program).

We would like to thank Dr. Dylan Nelson (Research Group Leader, University of Heidelberg) for providing the Python scripts which were used to generate all of the images used in this project and for his continuing scientific collaboration. We would also like to thank Dr. Allison Merritt for contributing to the visual inspection of thousands of galaxies in the pilot phase of this project.

The team members above took part in the initial phase of the visual classification of jellyfish galaxies in the pilot study: Yun et al., 2019.

Additional team members are further contributing to the extraction of scientific results from the IllustrisTNG simulations coupled with the results of this Zooniverse project, including:

Eric Rohr (PhD student)
Junia Goeller (PhD student).

Meet the team!

Annalisa was born and raised in Italy. She works with supercomputer simulations of virtual universes that represent large parts of the real universe to understand the formation and evolution of galaxies. She is now a research group leader at the Max Planck Institute for Astronomy in Heidelberg. Before that, she obtained her Bachelor and Master in Physics at the Universita' di Pisa, to then complete her PhD at the ETH in Zurich in 2010 with a thesis on constraining Inflation with observations of the cosmic web, under the supervisions of Cristiano Porciani. She worked as a postdoc at the University of California in Santa Cruz and at Harvard University in the groups of Prof. Piero Madau and Prof. Lars Hernquist, respectively, before reaching Germany in 2016.

Elad is a researcher at the Racah Institute of Physics at the Hebrew University in Jerusalem, and was previously at the Max Planck Institute for Astronomy in Heidelberg, in the research group of Annalisa Pillepich. He studies the formation and evolution of galaxies by combining insights from computer simulations, semi-analytic modelling and observations. Elad completed his PhD with Prof. Avishai Dekel at the Hebrew University studying the gas which fills galaxy clusters and the ways in which it can affect the galaxies in the cluster.

Kiyun is a PhD student at Yonsei University and was previously at the Max Planck Institute for Astronomy in the research group of Annalisa Pillepich. His research focuses on jellyfish galaxies - how to identify them in simulations, their properties and their environments. He lead the pilot study that preceded this project, wherein the jellyfish galaxies were visually identified by the team and used to study their incidence and properties.

Gandhali is a postdoctoral researcher at University College London, and was previously at the Max Planck Institute for Astronomy in Heidelberg, in the research group of Annalisa Pillepich. She studies the evolution of galaxies in a variety of environments using cosmological simulations. She completed her graduate studies at the University of Waterloo and McMaster University in Canada. Her PhD work, under the supervision of Prof. James Wadsley and Laura Parker, focused on the properties and evolution of galaxies in dense environments, known as galaxy clusters, which can drastically change the shape of the galaxies as well as their contents and the rate at which they form stars.

Martina was a postdoctoral researcher at the Max Planck Institute for Astronomy in Heidelberg, in the research group of Annalisa Pillepich. She studies several aspects of the star formation activity of galaxies in different environments and vertical stellar disk structure of MW-like galaxies, using the outcome of the IllustrisTNG cosmological simulations. During her PhD at the University Sapienza in Rome, she performed a series of direct N-body simulations aimed at shedding light on the interactions among the central cluster galaxy and its satellites.