Investigating star formation in Illustris TNG galaxy mergers

Abstract

Dwarf galaxies are the probable sources of the hot intra-cluster medium, a subject of a series of recent X-ray discoveries. Galaxy interaction trigger may lead to high star formation rates in these galaxies, that can lead to multiple core collapse supernovae and hot gas ejection. We studied the star formation rate history of merging galaxies in the IllustrisTNG 100-1, cosmological, magneto-hydrodynamic simulation focusing on mergers where one of the galaxies is a dwarf. We investigated the star formation rate and mass evolution of galaxies (progenitor), their dwarf merger companions (next progenitor) and their descendants at cosmological timescales with the use of the simulation’s merger trees. We processed different merger trees testing the robustness of our method and found that the results are consistent. Our results show that properties of galaxies in the compared merger trees are identical, only small differences occur. We will present our methodology and the comparison of three different merger trees, including the mass and star formation rate history of the merging galaxies.