PhD defence

Withstanding the cold: energy feedback in simulations of galaxies that include a cold interstellar medium

• E. Chaikin

Date

Tuesday 27 February 2024

Time

11:15 - 12:00 hour

Address

Academy Building
Rapenburg 73
2311 GJ Leiden

Supervisor(s)

• Prof.dr. J. Schaye
• dr. M. Schaller

Summary

Understanding how galaxies form, interact, and evolve comes largely from comparing theory predictions with observational data. Numerical simulations of galaxies provide the most accurate approach to testing the theory. They follow the non-linear evolution of gas and dark matter in great detail and incorporate numerous baryonic processes, among which are energy feedback from supernovae (SNe) and Active Galactic Nuclei (AGN). In this thesis, we show the results of the development of the new model COLIBRE for cosmological simulations of galaxy formation that include a cold interstellar medium. First, we present a new SN feedback recipe developed for COLIBRE, whereby SN energy is injected into the gas in both thermal and kinetic form, and the total energy and momentum of the system of gas and stars are exactly conserved. Second, we conduct a detailed comparison of different ways in which SN energy is distributed in the gas environment around young stellar populations. We present an algorithm that distributes SN energy statistically isotropically and employ it in COLIBRE. Third, by using our simulation setup originally developed to test COLIBRE’s SN feedback, we show that the radioactive isotope Fe60 that has been detected on Earth is likely of SN origin. Finally, we present the calibration of the SN and AGN feedback of the COLIBRE model using machine learning. We demonstrate that the calibrated COLIBRE simulations not only reproduce the observed data used in the calibration, but also agree with many other properties of observed galaxies to which the model was not calibrated.

PhD dissertations

Approximately one week after the defence, PhD dissertations by Leiden PhD students are available digitally through the Leiden Repository, that offers free access to these PhD dissertations. Please note that in some cases a dissertation may be under embargo temporarily and access to its full-text version will only be granted later.

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