Simulating the chemical enrichment of the intergalactic medium
Wiersma, R.P.C.
Citation
Wiersma, R. P. C. (2010, September 22). Simulating the chemical enrichment of the intergalactic medium. Retrieved from https://hdl.handle.net/1887/15972
Version: Corrected Publisher’s Version
License: Licence agreement concerning inclusion of doctoral thesis in the Institutional Repository of the University of Leiden
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S IMULATING THE
C HEMICAL E NRICHMENT
OF THE I NTERGALACTIC M EDIUM
S IMULATING THE
C HEMICAL E NRICHMENT
OF THE I NTERGALACTIC M EDIUM
Proefschrift
ter verkrijging van
de graad van Doctor aan de Universiteit Leiden,
op gezag van de Rector Magnificus prof. mr. P.F. van der Heijden, volgens besluit van het College voor Promoties
te verdedigen op woensdag 22 september 2010 te klokke 15.00 uur
door
Robert P.C. Wiersma
geboren te Collingwood in 1978
Promotiecommissie
Promotor: Prof. dr. Tim de Zeeuw Co-promotor: Dr. J. Schaye
Overige leden: Dr. J. Brinchmann
Prof. dr. S. Portegies Zwart Prof. dr. K. Kuijken
Dr. T. Theuns (Durham University)
Prof. dr. E. Tolstoy (Rijksuniversiteit Groningen)
The heavens proclaim the glory of God.
The skies display his craftsmanship.
PSALM19:1, NLT
Cover: “Space” by Orion and Esther Wiersma
Contents
1 Introduction 1
1.1 ’Simple’ Models . . . 5
1.1.1 Purely Analytical Calculations . . . 5
1.1.2 Numerical Calculations . . . 9
1.2 The OWLS project . . . 12
1.3 This Thesis . . . 14
1.3.1 Chapter 2 . . . 14
1.3.2 Chapter 3 . . . 14
1.3.3 Chapter 4 . . . 15
1.3.4 Chapter 5 . . . 15
1.4 Outlook . . . 16
2 Photoionization and the cooling rates of enriched, astrophysical plasmas 19 2.1 Introduction . . . 20
2.2 Method . . . 21
2.3 Photo-Ionization, metals, and cooling rates . . . 25
2.4 Effect on the WHIM . . . 29
2.5 The relative importance of different elements . . . 31
2.6 Discussion . . . 33
3 Chemical enrichment in cosmological, SPH simulations 37 3.1 Introduction . . . 39
3.2 Simulations . . . 41
3.3 Ingredients from stellar evolution . . . 45
3.3.1 Stellar initial mass function . . . 46
3.3.2 Stellar lifetimes . . . 48
3.3.3 Stellar yields . . . 48
3.3.4 SN type Ia rates . . . 54
3.4 Previous Work . . . 58
3.5 The mass ejected by a simple stellar population . . . 61
3.5.1 Implementation . . . 61
3.5.2 Results . . . 64
3.6 Implementation into SPH . . . 65
3.6.1 Enrichment scheme . . . 65
viii The Chemical Enrichment of the IGM
3.6.2 Smoothed metallicities . . . 67
3.7 The predicted distribution of metals . . . 72
3.7.1 Smoothed vs. particle metallicity . . . 78
3.8 Summary . . . 80
3.A Varying the size of the simulation box . . . 83
3.B Varying the resolution . . . 86
4 Determining the cosmic distribution of metals. 97 4.1 Introduction . . . 99
4.2 Method . . . 100
4.2.1 The REFERENCE model . . . 101
4.2.2 The Simulation Suite . . . 104
4.3 Results . . . 105
4.3.1 Overview . . . 107
4.3.2 Impact of energy feedback and metal-line cooling . . . 114
4.3.3 Wind Models . . . 119
4.3.4 Active Galactic Nuclei . . . 126
4.3.5 Stellar Initial Mass Function . . . 127
4.3.6 Other models . . . 131
4.3.7 Summary . . . 132
4.4 Conclusions . . . 135
5 The enrichment history of cosmic metals 143 5.1 Introduction . . . 144
5.2 Simulations . . . 145
5.3 When was the gas enriched? . . . 148
5.4 How massive were the objects that enriched the gas? . . . 154
5.5 What enriched the IGM and when? . . . 161
5.6 Conclusions . . . 163
Bibliography 168
Nederlandse Samenvatting 171
Curriculum Vitae 179
Nawoord 181
