eprintid: 36812
rev_number: 24
eprint_status: archive
userid: 9122
dir: disk0/00/03/68/12
datestamp: 2025-07-10 09:26:18
lastmod: 2025-07-14 18:00:54
status_changed: 2025-07-10 09:26:18
type: doctoralThesis
metadata_visibility: show
creators_name: Hoyer, Nils
title: The assembly of nuclear star clusters
subjects: ddc-500
subjects: ddc-520
divisions: i-130001
adv_faculty: af-13
cterms_swd: Dissertation
cterms_swd: Astronomie
abstract: The evolution of galaxies represents a hitherto unsolved area of modern astrophysics. Various dynamical effects play an important role in shaping galaxy centres making them extremely interesting to study in detail. Nuclear star clusters are often a key element of galaxy centres and feature both diverse and complex formation histories as well as extremely high stellar densities. Many aspects of nuclear star cluster formation are still uncertain and require new constraints to make full use of their ability as ideal laboratories for studying galaxy evolution and the growth of massive black holes that are located in their centres. An improved knowledge of nuclear star cluster assembly is especially relevant today in order to properly interpret the vast amount of upcoming data produced with all-sky surveys. I present in this dissertation various analyses of high-resolution observational data sets from space-based missions ranging between the X-ray and mid-infrared regimes and a new computer simulation of the assembly of massive star cluster populations. The first analysis reveals tight correlations between the properties of nuclear star clusters and old globular star clusters in the Milky Way indicating a potential common formation mechanism of the two cluster types. In a second analysis I identify nuclear star clusters with variable accretion signatures from massive black holes within them and provide upper limits for lower-mass systems in case of non-detections. I demonstrate in a third project that analysing the spectral energy distribution of the nuclear star cluster in the nearby massive spiral galaxy Messier 74 constrains the assembly history of both the host galaxy and a potential massive black hole in the star cluster’s centre. In addition to the projects that rely on observational data sets, I introduce a new simulation that is based on a dark matter-only computation and considers the co-formation of galaxies and massive star clusters. I show that my simulation can reproduce a number of observational quantities such as the mass function of young massive star clusters or the metallicity distribution of old globular clusters, both in nearby galaxies. I conclude by summarising the contents of this dissertation and by presenting future efforts that build on the
presented observational and numerical approaches.
date: 2025
id_scheme: DOI
id_number: 10.11588/heidok.00036812
ppn_swb: 1930464150
own_urn: urn:nbn:de:bsz:16-heidok-368121
date_accepted: 2025-07-02
advisor: HASH(0x5608d4082100)
language: eng
bibsort: HOYERNILSTHEASSEMBL20250702
full_text_status: public
place_of_pub: Heidelberg
citation:   Hoyer, Nils  (2025) The assembly of nuclear star clusters.  [Dissertation]     
document_url: https://archiv.ub.uni-heidelberg.de/volltextserver/36812/1/Library_Hoyer_Nils.pdf