Cover Page
The handle http://hdl.handle.net/1887/19107 holds various files of this Leiden University dissertation.
Author: Velander, Malin Barbro Margareta
Title: Studying dark matter haloes with weak lensing
Issue Date: 2012-06-20
Studying Dark Matter
Haloes with Weak Lensing
Studying Dark Matter Haloes with Weak Lensing
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 20 juni 2012 klokke 11.15 uur
door
Malin Barbro Margareta Velander
geboren te Lund, Zweden
in 1983
Promotiecommissie
Promotor: Prof. dr. K. H. Kuijken
Overige leden: Prof. dr. M. Franx
Prof. dr. A. Taylor (Edinburgh University, UK) Dr. H. Hoekstra
Dr. J. Brinchmann
For my husband
and our little one
Cover: Chinese Kite Cluster by Gabrian J. van Houdt
Table of Contents
1 Introduction 1
1.1 Cosmology . . . 1
1.1.1 The concordance model of cosmology . . . 1
1.1.2 Alternative models . . . 6
1.1.3 Cosmology probes . . . 7
1.2 Gravitational lensing overview . . . 11
1.2.1 Fundamentals of lensing . . . 11
1.2.2 Microlensing . . . 13
1.2.3 Strong lensing . . . 16
1.3 Weak lensing . . . 19
1.3.1 Convergence, shear and flexion . . . 19
1.3.2 Cosmic shear . . . 23
1.3.3 Galaxy-galaxy lensing . . . 25
1.3.4 Bullets and train wrecks . . . 29
1.3.5 Shape measurement methods . . . 32
1.4 This Thesis . . . 36
2 A new shape measurement method and its application to galaxies with colour gradients in weak lensing surveys 38 2.1 Introduction . . . 39
2.2 Theoretical background . . . 40
2.2.1 Shear and flexion . . . 40
2.2.2 Shapelets . . . 41
2.2.3 The MV pipeline . . . 43
2.3 Monochromatic tests . . . 45
2.3.1 GREAT08 . . . 45
2.3.2 FLASHES . . . 50
2.4 Non-monochromatic tests . . . 55
2.4.1 Analytical prediction . . . 55 i
TABLE OF CONTENTS
2.4.2 Simulations . . . 57
2.4.3 Results . . . 59
2.5 Conclusion . . . 62
3 Probing galaxy dark matter haloes in COSMOS with weak lensing flexion 64 3.1 Introduction . . . 65
3.2 Shear and flexion . . . 66
3.3 Shapelets . . . 67
3.3.1 The MV pipeline . . . 68
3.4 Testing the pipeline . . . 69
3.4.1 GREAT08 . . . 69
3.4.2 FLASHES . . . 70
3.4.3 Galaxy-galaxy simulations and bright object removal . . . 73
3.5 COSMOS analysis . . . 74
3.5.1 The COSMOS data set . . . 75
3.5.2 Data analysis . . . 75
3.5.3 Results . . . 76
3.5.4 Removing bright objects . . . 78
3.5.5 The effect of substructure . . . 78
3.5.6 Profile determination . . . 81
3.6 Discussion and conclusions . . . 83
3.A FLASHES results . . . 84
3.B COSMOS data analysis . . . 85
3.B1 Catalogue creation . . . 85
3.B2 PSF interpolation . . . 87
3.B3 CTI correction . . . 88
3.B4 Signal computation . . . 89
3.C High redshift results . . . 90
3.D Comparison with KSB . . . 90
4 The relation between galaxy dark matter haloes and baryons in the CFHTLS from weak lensing 93 4.1 Introduction . . . 94
4.2 Data . . . 95
4.2.1 Lens sample . . . 95
4.2.2 Source catalogue . . . 96
4.3 Method . . . 97
4.3.1 Weak galaxy-galaxy lensing . . . 97
4.3.2 The halo model . . . 98
4.4 Systematics tests . . . 100
4.4.1 Verification of the shear catalogue . . . 100
4.4.2 Seeing test . . . 101
4.5 Luminosity trend . . . 103
4.5.1 Photometric redshift error corrections . . . 107
4.5.2 Luminosity scaling relations . . . 109
4.5.3 Satellite fraction . . . 113
4.6 Stellar mass trend . . . 113
4.6.1 Stellar mass scaling relations . . . 115
4.7 Discussion and conclusions . . . 120 ii
TABLE OF CONTENTS
4.A Detailed luminosity bins . . . 121
4.B Detailed stellar mass bins . . . 124
5 Constraining cluster profiles with weak lensing shear and flex- ion 127 5.1 Introduction . . . 128
5.2 Cluster lensing formalism . . . 129
5.2.1 Shear and flexion . . . 130
5.2.2 Contribution from the BCG . . . 131
5.2.3 Contribution from centred cluster dark matter haloes . . 132
5.2.4 Contribution from a cluster population with miscentred BCGs . . . 132
5.2.5 Other contributions . . . 134
5.3 Results . . . 135
5.3.1 Mass dependence . . . 135
5.3.2 Concentration dependence . . . 137
5.3.3 Offset width dependence . . . 139
5.4 Conclusions . . . 141
Bibliography 143
Nederlandse samenvatting 157
Svensk sammanfattning 162
Publications 166
Curriculum Vitæ 168
Afterword 170
iii
