The High Redshift Universe: Galaxies and the Intergalactic Medium Koki Kakiichi M¨unchen2016 The High Redshift Universe: Galaxies and the Intergalactic Medium Koki Kakiichi Dissertation an der Fakult¨atf¨urPhysik der Ludwig{Maximilians{Universit¨at M¨unchen vorgelegt von Koki Kakiichi aus Komono, Mie, Japan M¨unchen, den 15 Juni 2016 Erstgutachter: Prof. Dr. Simon White Zweitgutachter: Prof. Dr. Jochen Weller Tag der m¨undlichen Pr¨ufung:Juli 2016 Contents Summary xiii 1 Extragalactic Astrophysics and Cosmology 1 1.1 Prologue . 1 1.2 Briefly Story about Reionization . 3 1.3 Foundation of Observational Cosmology . 3 1.4 Hierarchical Structure Formation . 5 1.5 Cosmological probes . 8 1.5.1 H0 measurement and the extragalactic distance scale . 8 1.5.2 Cosmic Microwave Background (CMB) . 10 1.5.3 Large-Scale Structure: galaxy surveys and Lyα forests . 11 1.6 Astrophysics of Galaxies and the IGM . 13 1.6.1 Physical processes in galaxies . 14 1.6.2 Physical processes in the IGM . 17 1.6.3 Radiation Hydrodynamics of Galaxies and the IGM . 20 1.7 Bridging theory and observations . 23 1.8 Observations of the High-Redshift Universe . 23 1.8.1 General demographics of galaxies . 23 1.8.2 Lyman-break galaxies, Lyα emitters, Lyα emitting galaxies . 26 1.8.3 Luminosity functions of LBGs and LAEs . 26 1.8.4 Lyα emission and absorption in LBGs: the physical state of high-z star forming galaxies . 27 1.8.5 Clustering properties of LBGs and LAEs: host dark matter haloes and galaxy environment . 30 1.8.6 Circum-/intergalactic gas environment of LBGs and LAEs . 31 1.8.7 State of the IGM at 2 < z < 5..................... 33 1.9 Reionization Probes . 36 1.9.1 When did reionization occur? . 37 1.9.2 What is the history of reionization? . 38 1.9.3 What is the morphology of reionization? . 41 1.9.4 What is the source of reionization? . 42 1.10 Conclusion . 44 vi CONTENTS 2 Lyα Emitting Galaxies as a Probe of Reionization 45 2.1 Backgrounds . 45 2.2 Cosmological H I content . 47 2.2.1 Observational Constraints on H I in the Post-Reionization Epoch . 49 2.2.2 Observational Constraints on H I During Reionization . 49 2.2.3 Theoretical expectations for H I .................... 50 2.3 Cosmological Lyα radiative transfer . 53 2.3.1 Lyα Opacity from Large-Scale H I Patches . 54 2.3.2 Lyα Opacity from Small-Scale Absorbers . 55 2.4 Simulations . 56 2.4.1 Hydrodynamical Simulations of the IGM . 56 2.4.2 Radiative Transfer Simulations . 57 2.4.3 Mock Galaxy Catalogue . 61 2.5 Results . 62 2.5.1 Lyα Luminosity Function . 62 2.5.2 The Red Damping Wing in Bubble Models . 64 2.5.3 The Red Damping Wing in Web Models . 66 2.5.4 Lyα Red Damping Wing in Web-Bubble Models . 71 2.5.5 Probability Distribution Functions for TIGM . 73 2.5.6 Simultaneously Constraining the H I Fraction and the Topology of Reionization . 75 2.6 Discussion & Conclusions . 80 3 Reionization by Galaxies and QSOs and the Thermal State of the IGM 83 3.1 Backgrounds . 83 3.2 Simulations . 85 3.2.1 Hydrodynamical simulations of the IGM . 85 3.2.2 Multi-frequency radiative transfer simulations . 86 3.2.3 Source model: galaxies . 88 3.2.4 Source model: QSO . 90 3.3 Results . 91 3.3.1 H II and He II=He III regions in a galaxy- or QSO-driven reionization model . 93 3.3.2 Effect of X-rays and secondary ionization . 97 3.3.3 H II and He II=He III regions in a reionization model driven both by galaxies and a QSO . 99 3.3.4 Dependence on the properties of a QSO . 104 3.4 Thermal state of the IGM . 108 3.4.1 Thermal state of the IGM in a galaxy- or QSO-driven reionization model . 108 3.4.2 Effect of X-rays and secondary ionization . 112 3.4.3 The thermal state of the IGM in a reionization model driven both by galaxies and a QSO . 113 Inhaltsverzeichnis vii 3.5 Comparison with previous work . 120 3.5.1 Can a QSO change the morphology of H II regions in a distinctive way?120 3.6 Observational Implications . 121 3.7 Conclusions . 123 4 Radio signals from the high redshift QSO environments 125 4.1 Backgrounds . 125 4.2 Cosmological radio signals of the IGM . 126 4.2.1 H I 21 cm signal . 126 3 4.2.2 He II 3.46 cm signal . 126 4.3 H I 21 cm signal around high redshift QSOs . 128 4.3.1 The full coupling limit . 129 4.3.2 The kinetic coupling limit . 129 3 4.4 He II 3.46 cm signal around high redshift QSOs . 130 4.5 Discussions . 132 5 Conclusions and Prospects 135 A Appendix 1 139 A.1 The mass-weighted neutral fraction in the post-reionized universe . 139 A.2 Effective optical depth of dynamical small-scale absorbers . 140 A.3 Abundance matching . 142 A.4 Lyα RT through the IGM: computing the line-of-sight skewers and optical depth . 142 A.5 Intrinsic Lyα fraction . 144 Acknowledgments 172 viii Inhaltsverzeichnis List of Figures 1.1 Hubble Ultra Deep Field image . 2 1.2 The sketch of the Epoch of Reionization and Cosmic Dawn . 3 1.3 The large-scale structure of the universe . 9 1.4 Hubble diagram . 10 1.5 CMB power spectrum . 11 1.6 List of galaxy surveys . 12 1.7 The evolution of the specific star formation rate of galaxies . 24 1.8 Stellar mass functions . 25 1.9 The star formation rate - stellar mass relation . 26 1.10 UV luminosity function . 27 1.11 Lyα luminosity function . 28 1.12 The evolution of Lyα fraction . 29 1.13 Lyα forest - galaxy cross-correlation function . 31 1.14 2D pixel optical depth map . 33 1.15 The UV background evolution . 34 1.16 The thermal history of the IGM . 35 1.17 The Gunn-Peterson optical depth . 38 1.18 Cosmic star formation rate density . 43 2.1 Cosmic H I contents . 48 2.2 Theoretical model of the reionization history . 51 2.3 The map of reionization . 59 2.4 The map of the neutral hydrogen fraction . 59 2.5 The map of the neutral hydrogen fraction for the hybrid model . 60 2.6 Lyα luminosity function . 63 2.7 The Lyα damping wing optical depth . 65 2.8 Analytic model of Lyα damping wing in the bubble models . 66 2.9 Analytic model of Lyα damping wing in the web models . 67 2.10 H I Column Density Distribution Functions . 68 2.11 Contribution of absorbers to Lyα damping wing . 69 2.12 The distribution and the kinematics of the galaxy-absorber pairs . 70 2.13 Lyα damping wing in the hybrid web-bubble models . 72 2.14 IGM transmission factor . 74 x Abbildungsverzeichnis 2.15 The equivalent width distribution . 76 2.16 Lyα fraction . 78 3.1 The total ionizing photon emissivity . 89 3.2 Model spectra of galaxies and a QSO . 90 3.3 3D visualization of the H II, He II, and He III fractions . 92 3.4 Maps of H II , He II (middle), and He III (bottom) fractions . 94 3.5 Distribution of the H II and He III I-front radii . 95 3.6 Spherically averaged profiles of H II, He II, and He III fractions . 96 3.7 Distribution of the H II=He III I-front position and thickness . ..