Cover Page
The handle http://hdl.handle.net/1887/31710 holds various files of this Leiden University dissertation.
Author: Caputo, Daniel P.
Title: The Great Collapse
Issue Date: 2015-01-22
The Great Collapse
Daniel P Caputo
Cover: “e Treachery of Simulations” by author.
ISBN: 978-94-6108-917-5
© 2015 Daniel Caputo
The Great Collapse
Proefschrift
ter verkrijging van
de graad van Doctor aan de Universiteit Leiden, op gezag van Rector Magnificus prof. mr. C.J.J.M. Stolker,
volgens besluit van het College voor Promoties te verdedigen op donderdag 22 januari 2015
klokke 13:45 uur
door
Daniel P Caputo
geboren te Massachusetts, USA in 1981
Promotiecommissie
Promotor: Prof. dr. Simon Portegies Zwart
Overige leden: Dr. Alessandro Patruno (Universiteit Leiden)
Prof. dr. Roberto Capuzzo Dolcetta (Sapienza–Università di Roma) Prof. dr. omas Tauris (Universität Bonn)
Prof. dr. Huub Röttgering (Universiteit Leiden)
To Samantha, my love, at the end of our European honeymoon.
Contents
1 Introduction 1
1.1 is Work . . . 3
1.1.1 Initial Virial Temperature (Chapter 2) . . . 3
1.1.2 Mass Segregation in a Collapsing Cluster (Chapter 3) . 4 1.1.3 e Number of IMBHs (Chapter 4) . . . 4
1.1.4 Supernova in Hierarchical Star Systems (Chapter 5) . 4 2 Subvirial Systems 7 2.1 Introduction . . . 8
2.1.1 Violent Relaxation . . . 8
2.1.2 Notation . . . 9
2.2 Simulations . . . 9
2.2.1 AMUSE . . . 9
2.2.2 Initial Conditions . . . 10
2.3 Results and Discussion . . . 11
2.3.1 Escape Fraction . . . 12
2.3.2 Mass Segregation . . . 15
2.3.3 Time-scales . . . 19
2.3.4 Minimum Cluster Radius . . . 21
2.3.5 Observables . . . 22
2.4 Application to an observed cluster: R136 . . . 24
2.4.1 Observed Parameters . . . 24
2.4.2 From N-body to Physical Units . . . 25
2.4.3 Initial Virial Temperature of R136 . . . 27
2.4.4 Other Young Clusters . . . 29
2.5 Conclusion . . . 30
3 Mass Segregation 33 3.1 Introduction . . . 34
3.2 Method . . . 34
3.2.1 Minimum Spanning Tree Method . . . 35
3.2.2 Nearest Neighbor Method . . . 35
3.3 Comparing Results . . . 36
3.3.1 Measurements of the Mass Segregation . . . 36
3.3.2 Speed . . . 40
3.4 Results and Discussion . . . 42
3.4.1 Simulation Methods . . . 42
3.4.2 Mass Segregation . . . 43
3.4.3 Effect of the Initial FoV on Mass Segregation . . . 46
3.5 Conclusion . . . 47
4 Number of Intermediate Mass Black Holes 49 4.1 Introduction . . . 50
4.2 Observational Constraints HLX-1 and M82 X-1 . . . 50
4.3 Methods . . . 51
4.3.1 Mass Transfer . . . 52
4.3.2 Mass Function . . . 53
4.4 Results and Discussion . . . 54
4.4.1 e Mass of HLX-1’s Companion and the Mass Func- tion Around the IMBH . . . 55
4.4.2 e Number of IMBHs . . . 56
4.4.3 IMBHs in Relation to Other Black Holes . . . 58
4.5 Conclusion . . . 59
4.6 Acknowledgments . . . 60
5 Supernova in Multiple-Star Systems 63 5.1 Introduction . . . 64
5.2 Calculation of post-SN parameters . . . 65
5.2.1 Binary systems . . . 65
5.2.2 Hierarchical triple systems . . . 70
5.2.3 An example of the effect of a supernova in a hierarchi- cal triple . . . 76
5.2.4 Hierarchical systems of multiplicity > 3 . . . . 78
5.3 Application: Formation of J1903+0327 . . . 83
5.3.1 Initial conditions . . . 84
5.3.2 Simulations . . . 85
5.4 Conclusion . . . 90
5.5 Acknowledgements . . . 91
6 Summary 93
6.1 e Role of Simulations . . . 94
6.2 Collapsing Clusters . . . 95
6.2.1 Taking a Star Cluster’s Temperature . . . 95
6.2.2 Why do all of the Big Stars Clump Together? . . . 96
6.3 Collapsing Stars . . . 97
6.3.1 Supernova . . . 97
6.3.2 Intermediate Mass Black Holes . . . 98
7 Samenvatting 99 7.1 De rol van simulaties . . . 100
7.2 Instortende sterrenhopen . . . 101
7.2.1 De temperatuur van een sterrenhoop bepalen . . . 102
7.2.2 Waarom klonteren alle grote sterren samen? . . . 103
7.3 Ineenstortende Sterren . . . 104
7.3.1 Supernova . . . 104
7.3.2 Middelgrote Zwarte Gaten . . . 105
List of publications 107
Bibliography 109
Curriculum Vitae 119
Acknowledgements 121
