The First Quiescent Galaxies in TNG300

Undergraduate Honors Thesis

Citations

Citeable URL: https://scholar.colorado.edu/concern/undergraduate_honors_theses/6t053h55r

Abstract

By the time the Universe was 3 billion years old, half of its massive galaxies had stopped forming new stars [1, 2], but the variations in the time-scales and structural factors involved in their quenching processes often evade explanation. These quiescent galaxies appear to be unable to form stars because they lack reservoirs of cold, star-forming gas [3, 4, 1]. When observed at high redshifts, they are exceedingly compact [5, 6, 7, 8], which in principle allows for more expedient gas accretion onto their supermassive black holes (SMBHs). If a galaxy’s central SMBH accretes rapidly enough, an active galactic nucleus (AGN) is formed, which serves as an incredibly luminous and persistent source of electromagnetic radiation [9, 10, 11]. By preventing further accumulation of cold gas and dust in the central regions of a galaxy [12, 13], AGN feedback is proposed to prohibit quiescent galaxies from rejuvenating and developing dense stellar cores later in time (but see also [14]). This feedback from early black holes has thus likely played a pivotal role in the quenching of early and massive galaxies [15, 16, 17], but causal evidence linking AGN feedback to quenching has been nearly impossible to establish observationally. This empirical uncertainty necessitates the use of cosmological simulations in studies of AGN feedback.

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Additional Information

To write this honors thesis, I repurposed my first author paper, which was published in the Monthly Notices of the Royal Astronomical Society in June of 2023. This paper has the same title ("The first quiescent galaxies in TNG300"), and as I conducted the research that was published, my honors thesis substantially uses information from that manuscript.

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