Multi-Wavelength Surveys of Extreme Infrared Populations Markos Trichas Astrophysics Group Department of Physics Imperial College London · 2008 · Abstract of Thesis Author Markos Trichas Title of Thesis Multi-Wavelength Surveys of Extreme Infrared Populations Degree PhD This Thesis presents a study of galaxies and quasars from the viewpoint of their optical, infrared and X-ray properties by combining optical data from Gemini and WIYN with near to far-IR and optical data from the SWIRE survey and X-ray data from Chandra. This work represents the largest existing optical spectroscopic survey in ELAIS-N1 with ∼300 reliable spectroscopic redshifts and the largest X- ray survey, in the same field, which has extended the previous X-ray coverage in ELAIS-N1 by a factor of 12 and has detected more than 600 X-ray sources. Optical spectroscopy is used both to calibrate photometric redshift techniques and distin- guish between star forming galaxies and quasars. The merged X-ray, optical and infrared catalogue is used to determine spectral energy distributions and correctly identify and characterize AGN, star forming galaxies and the link between black hole growth and star formation in the host galaxy. 2 to my beloved Sophia 3 Contents Abstract 1 List of Tables 9 List of Figures 20 Declaration and Copyright 21 Acknowledgments 22 1 Introduction 25 1.1 Overview . 25 1.2 A Broad Picture of the Universe . 26 1.3 The Infrared Region . 28 1.3.1 The Near-Infrared Region . 29 1.3.2 The Mid-Infrared Region . 30 1.3.3 The Far-Infrared Region . 32 1.3.4 The Submillimeter Region . 32 1.4 Space–based Infrared Telescopes . 32 1.4.1 IRAS . 33 1.4.2 ISO . 35 1.4.3 AKARI . 39 1.4.4 HERSCHEL . 41 1.5 Origin of Extragalactic Infrared Emission . 43 1.5.1 Infrared Source Components . 47 1.5.2 Luminous Infrared Galaxies . 53 1.6 Star Formation History . 56 1.6.1 Population Synthesis Modeling . 57 1.6.2 Ultraviolet . 59 1.6.3 Recombination Lines . 59 4 1.6.4 Forbidden Lines . 60 1.6.5 Infrared and Submillimetre . 60 1.6.6 Radio and X–ray . 61 1.6.7 Comparison of Star Formation Rates . 63 1.6.8 Chemical Evolution Models . 66 1.6.9 Source Count Models . 67 1.7 Continuation . 67 2 Spitzer and SWIRE 69 2.1 Overview . 69 2.2 Spitzer . 70 2.2.1 Observing Modes . 70 2.2.2 IRAC . 71 2.2.3 MIPS . 73 2.2.4 IRS................................. 74 2.3 Spitzer Science Program . 75 2.4 SWIRE . 82 2.4.1 Selection of SWIRE Fields . 84 2.4.2 Observations . 85 2.4.3 Multi-Wavelength Supporting Observations . 86 2.4.4 Optical Data . 88 2.4.5 Status and Results . 89 2.5 Future . 91 2.6 Continuation . 91 3 Multi-Object Spectroscopy of SWIRE ELAIS-N1 Populations 93 3.1 Overview . 93 3.2 The Gemini Multi-Object Spectrograph North . 94 3.2.1 General Characteristics . 94 3.2.2 MOS . 94 3.2.3 IFU . 96 3.2.4 Nod & Shuffle . 96 3.3 WIYN Hydra . 98 3.4 Selection and Observations . 99 3.4.1 GMOS . 99 3.4.2 WIYN . 100 3.5 Data Reduction . 102 3.5.1 GMOS . 102 5 3.5.2 WIYN . 105 3.6 Cross-Correlation with SWIRE . 109 3.7 Number of Spectra and Object Classes . 113 3.8 Confidence Classes . 113 3.9 Redshift Distribution . 114 3.10 Ultra/Hyper Luminous Infrared Galaxies . 116 3.10.1 HLIRG . 117 3.10.2 ULIRG . 118 3.11 Summary . 120 3.12 Continuation . 120 4 Comparison with SWIRE Photometry 125 4.1 Overview . 125 4.2 Introduction . 126 4.2.1 Photometric Redshift Codes . 126 4.2.2 Photometric Redshifts from SWIRE . 127 4.2.3 Template SEDs . 129 4.2.4 Template Fitting . 131 4.2.5 Mid IR SED fitting . 132 4.3 Spectroscopic Comparisons . 132 4.4 Infrared Populations . 134 4.5 Emission Line Diagnostics . 139 4.6 Comparison with Colour-Colour Diagrams . 143 4.7 Summary . 145 4.8 Continuation . 147 5 The ELAIS-N1 Chandra Shallow Survey 148 5.1 Overview . 148 5.2 Introduction . 149 5.3 Chandra X-Ray Observatory and ACIS-I . 154 5.4 Observations and Data Reduction . 155 5.5 Cross Correlation with SWIRE . 158 5.6 Optical Spectroscopy . 161 5.7 Redshift Distributions . 161 5.8 Results . 166 5.9 Summary . 172 5.10 Continuation . 174 6 6 X-ray/ 70µm SWIRE Sources Unveil Evidence for AGN Star- Formation Connection 175 6.1 Overview . 175 6.2 Introduction . 176 6.2.1 The Need for Multi-Wavelength Data . 179 6.3 Data . 183 6.3.1 ELAIS-N1 . 184 6.3.2 Lockman Hole . 184 6.3.3 CDF-S . 185 6.4 Selection of the Sample . 187 6.5 Spectral Energy Distributions . 189 6.6 Results . 190 6.7 Discussion . 194 6.8 Conclusion . 198 7 Conclusions 200 Appendix 204 A Catalogue of Properties of SWIRE Sources Observed with GMOS and WIYN 204 B Catalogue of Properties of SWIRE Sources Observed with Chandra ACIS-I 213 C Catalogue of Properties of SWIRE Sources Observed with Chandra ACIS-I without Optical Associations 225 Bibliography 230 7 List of Tables 1.1 Basic cosmological parameters for the best-fit ΛCDM model based on the third year WMAP data [325]. 27 2.1 Spitzer’s main properties . 70 2.2 IRAC main properties [102]. Sensitivities are indicative in low back- ground sky. Confusion is not included. 73 2.3 MIPS main properties [269]. Sensitivities are indicative in low back- ground sky. Confusion is not included. 74 2.4 IRS main properties [153]. Sensitivities are indicative in low back- ground sky. Confusion is not included. 75 2.5 SWIRE Sensitivities (5σ) and lower flux limits for inclusion in the SWIRE catalogues [331]. Sources were required to be detected at 3.6 and 4.5 µm................................. 76 2.6 The final six SWIRE Fields [210]. 77 2.7 Imaging Surveys within SWIRE Fields [210]. 83 2.8 Number of infrared populations according to SED fitting of all SWIRE sources with optical associations [283]. 88 3.1 GMOS-N Gratings [3]. 94 3.2 Specifications of the GMOS-N instrument [150]. ..