Mining Illustris: Cosmological Histories of Major-Merger Galaxy Pairs

The Illustris project is a publicly accessible set of large-scale cosmological simulations. In this work, we improve upon an earlier study in which major-merger galaxies were visually identified and investigated with regards to their star formation rates. Using the same criteria, which includes the potential pairs’ spatial separation (<20 kpc), relative velocity (<500km/s), mass ratio (<2.5), and relative K band (<1), python code was written to optimize the sample size of major-merger pairs. We then classified each pair by morphology and compared them against observations of SDSS-2MASS selected galaxy pairs. We hope that the results of this study will give greater insights into why galaxy morphology affects star formation rate within major-mergers. This study has also laid down the ground-work to use data from the highly anticipated Illustris TNG, which when released will hopefully provide for a much larger sample size.