Cover Page
The handle http://hdl.handle.net/1887/65535 holds various files of this Leiden University
dissertation.
Author: Matthee, J.J.A.
Title: Identifying the origins of galaxy formation
Issue Date: 2018-09-19
Identifying the origins of
galaxy formation
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 woensdag 19 september 2018
klokke 10:00 uur
door
Jorryt Johan Anton Matthee
geboren te Utrecht in 1990
Promotiecommissie
Promotor: Prof. dr. Huub R¨ottgering Promotor: Prof. dr. Joop Schaye
Co-promotor: Dr. David Sobral (Lancaster University)
Overige leden: Prof. dr. Richard Ellis (University College London) Prof. dr. Andrea Ferrara (Scuola Normale Superiore Pisa) Prof. dr. Marijn Franx
Dr. Jacqueline Hodge Prof. dr. Paul van der Werf
For those born in less favourable spacetime locations
Front cover: Logarithmic spiral where the radius of each quarter increases with growth factor φ = 1+2√5, the golden ratio. From small to large: temperature fluctuations of the cosmic microwave background observed by the Planck satellite; simulated large-scale structure of dark matter in the universe in the EAGLE simulation; NASA/Hubble Space Telescope image of The Pillars of Creation in the Eagle nebula based on observations in the [Sii], Hα and [Oiii] filters; artist impression of the CR7 galaxy, ESO/Kornmesser; part of the COSMOS field imaged in the near-infrared using J, H and K filters on VIRCAM as part of the UltraVISTA survey; simulated large-scale structure of the universe in dark matter, gas and stars in the EAGLE simulation.
Back cover: From bottom-left to top-right: stylised photograph from the Isaac Newton Telescope on La Palma; drawing from the Moon by Galileo Galilei in 1610 based on the first astronomical usage of a telescope; drawing of Saturn by Christiaan Huygens in 1698; illustration of the NASA/GALEX satellite;
drawing of the Whirlpool galaxy (M51) by Lord Rosse in 1850; illustration of the spectrum of a Lyman-α photon; hexagonal cut-outs of observations used in this thesis from the INT, Subaru and the HST.
ISBN 978-94-028-1132-2
i
Contents
1 Introduction 1
1.1 Historical, physical and methodological framework . . . 2
1.1.1 History and cosmology . . . 2
1.1.2 Methodology . . . 3
1.2 Galaxy formation: theoretical perspective . . . 5
1.2.1 Structure formation in a ΛCDM Universe . . . 5
1.2.2 Gas cooling, star and black formation and feedback . . . 6
1.2.3 The star formation history of the Universe . . . 10
1.2.4 Chemical enrichment . . . 10
1.2.5 Reionization . . . 11
1.3 Galaxy formation: observational perspectives . . . 13
1.3.1 Observational tools . . . 13
1.3.2 What do galaxy colours tell us . . . 16
1.3.3 The physics encoded in nebular emission lines . . . 17
1.3.4 Studying galaxy formation with the Lyα emission line . . . 19
1.3.5 Sample selection methods . . . 22
1.4 This thesis, outlook . . . 23
1.4.1 Challenges & Open questions . . . 23
1.4.2 This thesis . . . 24
2 Identification of the brightest Lyα emitters at z = 6.6: implications for the evolution of the luminosity function in the reionization era 27 2.1 Introduction . . . 28
2.2 Observations & Data reduction . . . 31
2.3 Selecting Lyman-α emitters at z=6.6 . . . 35
2.4 Number counts, completeness and corrections for filter profile bias 46 2.5 Lyα Luminosity function at z=6.6 . . . 53
2.6 Discussion . . . 57
2.7 Conclusions . . . 64
3 Spectroscopic properties of luminous Lyα emitters at z ≈ 6−7 and comparison to the Lyman-break population 67 3.1 Introduction . . . 68
3.2 Sample & Observations . . . 69
3.3 Results . . . 72
3.4 Properties of newly confirmed LAEs . . . 75
3.5 Discussion . . . 80
ii CONTENTS
3.6 Conclusions . . . 94
3.A Galaxy compilation . . . 96
4 On the evidence for PopIII-like stellar populations in the most lumi- nous Lyman-α emitters at the epoch of reionization 99 4.1 Introduction . . . 100
4.2 Sample and Spectroscopic observations . . . 103
4.3 Measurements and SED fitting . . . 109
4.4 Discovery of the most luminous Lyα emitters . . . 111
4.5 SED fitting CR7 . . . 114
4.6 Discussion . . . 120
4.7 Conclusions . . . 124
4.A Summaries of articles interpreting CR7 . . . 127
4.B Comparison to Bowler et al. (2017b) . . . 130
4.C Comparison to Shibuya et al. (2018) . . . 132
5 ALMA reveals metals yet no dust within multiple components in CR7 133 5.1 Introduction . . . 134
5.2 UV properties of CR7 . . . 136
5.3 ALMA data . . . 137
5.4 Resolved [Cii] emission . . . 140
5.5 IR continuum . . . 146
5.6 The SFR-L[CII]relation . . . 150
5.7 Discussion . . . 154
5.8 Conclusions . . . 156
6 Confirmation of double peaked Lyα emission atz= 6.593: witnessing a galaxy directly contributing to the reionization of the Universe 161 6.1 Introduction . . . 162
6.2 Data . . . 164
6.3 Is COLA1 a LAE at z=6.59 or an [Oii] emitter at z=1.47? . . . . 169
6.4 Properties of COLA1 – a unique LAE at z=6.6 . . . 172
6.5 Discussion: witnessing a galaxy reionising its surroundings . . . . 179
6.6 Summary . . . 188
7 The CALYMHA survey: Lyα escape fraction and its dependence on galaxy properties atz=2.23 191 7.1 Introduction . . . 192
7.2 Sample and Observations . . . 194
7.3 Measurements . . . 196
7.4 Stacking method . . . 202
7.5 Direct measurements for individual galaxies . . . 205
7.6 Correlations between Lyα escape and galaxy properties . . . 211
7.7 Extended emission . . . 215
7.8 Discussion . . . 217
7.9 Conclusions . . . 223
Contents iii 8 The production and escape of Lyman-Continuum radiation from star-
forming galaxies atz∼2 and their redshift evolution 227
8.1 Introduction . . . 228
8.2 Galaxy sample . . . 230
8.3 GALEX UV data . . . 234
8.4 The escape fraction of ionizing photons . . . 235
8.5 Constraining fescof HAEs from the ionizing background . . . 239
8.6 The ionizing properties of star-forming galaxies at z=2.2 . . . 245
8.7 Implications for reionization . . . 252
8.8 Conclusions . . . 253
9 Bo¨otes-HiZELS: an optical to near-infrared survey of emission-line galaxies atz=0.4−4.7 261 9.1 Introduction . . . 262
9.2 Observations & data . . . 263
9.3 Data reduction & Catalogue production . . . 266
9.4 Classifying line-emitters . . . 269
9.5 Number densities . . . 276
9.6 Properties of line-emitters . . . 286
9.7 Conclusions . . . 290
10 The origin of scatter in the stellar mass - halo mass relation of central galaxies in the EAGLE simulation 297 10.1 Introduction . . . 298
10.2 Methods . . . 299
10.3 Correlations between stellar mass and DMO halo properties . . . . 308
10.4 Sources of scatter . . . 312
10.5 A Parametric description for predicting stellar masses . . . 317
10.6 Evolution . . . 320
10.7 Discussion . . . 320
10.8 Conclusions . . . 325
11 The origin of scatter in the star formation rate - stellar mass relation in EAGLE 331 11.1 Introduction . . . 332
11.2 Methods . . . 333
11.3 The amount of scatter . . . 335
11.4 How long galaxies remain above/below the main sequence . . . . 339
11.5 The origin of long time-scale correlations . . . 344
11.6 Relation with the growth of black hole mass . . . 351
11.7 Discussion . . . 356
11.8 Summary . . . 359
12 Star-forming galaxies are predicted to lie on a fundamental plane of mass, star formation rate and α-enhancement 365 12.1 Introduction . . . 366
12.2 Methods . . . 367
iv CONTENTS
12.3 The scatter in 2D and 3D mass - metallicity relations . . . 368 12.4 Discussion . . . 373
Nederlandse samenvatting 377
Bibliography 391
Publications 409
Curriculum Vitae 413
Acknowledgements 415
