Our Projects

I am one of the developers of the IllustrisTNG simulations and co-PI of the TNG50 simulation. These are gravity + magnetohydrodynamics simulations of large cosmological volumes that simultaenously resolve thousands of galaxies therein. In my team, we have extracted novel and useful sicentific notions from IllustrisTNG across a wide range of topics: see below and see more at the IllustrisTNG webpage

eROSITA has been launched in 2019 and is delivering an unprecedented all-sky map of the X-ray universe, including about hundred of thousands galaxy clusters. These can be used to place constraints on our cosmological models, including the level and evolution of Dark Energy. In parallel, we can and need to use simulations to quantify and predict the properties of the intra-cluster plasma, including its observational signatures as well as the effects of magnetic fields, shocks and feedback from the central super massive black holes.

We use simulations to quantify the effects of environment into the evolution of galaxies, their star formation activity, morphologies, and stellar and gaseous content. For example, satellite galaxies orbiting within the potential well of massive galaxy clusters undergo stripping of their materials, including the gas which sometimes produce extended wakes, or Jellyfish Galaxies. See our Citizen Scientist Project on Zooniverse: https://www.zooniverse.org/projects/apillepich/cosmological-jellyfish

One of the most intriguing challenges of our field is to understand our Galaxy, the Milky Way and our nieghbor Andromeda. We aim to model all aspects of it. We develop and use simulations (TNG0, IllustrisTNG, Illustris and Eris) to understand how special our Galaxy and Andromeda are, how they formed and how to interpret observational data.

Simulations have shown that galaxies assemble their stars by both making them (star formation) and by accreting and merging with other galaxies (accretion). Many of these accreted or ex-situ stars can be found at large distances around galaxies, forming the so called stellar haloes. We use simulations to quantify the assembly of galaxies and their stellar haloes across these different assembly channels, make predictions for future surveys and do comparisons to observations.

Simulations including only the effects of gravity (and hence only dark matter) have provided an exquisitely precise picture of the properties and distribution of dark matter, in haloes and across the large scale structure. However, recently, simulations including star formation, gas physics and feedback seem to suggest that such picture is more complex than anticipated…