ǂThe ǂdark energy survey : ǂthe ǂstory of a cosmological experiment

"This book is about the Dark Energy Survey, a cosmological experiment designed to investigate the physical nature of dark energy by measuring its effect on the expansion history of the universe and on the growth of large-scale structure. The survey saw first light in 2012, after a decade of planning, and completed observations in 2019. The collaboration designed and built a 570-megapixel camera and installed it on the four-metre Blanco telescope at the Cerro Tololo Inter-American Observatory in the Chilean Andes. The survey data yielded a three-dimensional map of over 300 million galaxies and a catalogue of thousands of supernovae. Analysis of the early data has confirmed remarkably accurately the model of cold dark matter and a cosmological constant. The survey has also offered new insights into galaxies, supernovae, stellar evolution, solar system objects and the nature of gravitational wave events. A project of this scale required the long-term commitment of hundreds of scientists from institutions all over the world. The chapters in the first three sections of the book were either written by these scientists or based on interviews with them. These chapters explain, for a non-specialist reader, the science analysis involved. They also describe how the project was conceived, and chronicle some of the many and diverse challenges involved in advancing our understanding of the universe. The final section is trans-disciplinary, including inputs from a philosopher, an anthropologist, visual artists and a poet. Scientific collaborations are human endeavours and the book aims to convey a sense of the wider context within which science comes about. This book is addressed to scientists, decision makers, social scientists and engineers, as well as to anyone with an interest in contemporary cosmology and astrophysics"-- Provided by publisher Half Title Page Title Page Copyright Page Contents Foreword Preface Acknowledgements Chapter -1: Introduction to the Dark Energy Survey Project and Science: What Have We Learned So Far? −1.1 What is dark energy? −1.2 The Dark Energy Survey −1.3 The context of dark energy observations −1.4 Four probes of dark energy −1.5 DES joint galaxy clustering and weak lensing: Year 1 cosmology results −1.6 DES-SN Year 3 cosmology results −1.7 Non-dark energy results −1.8 Josh Frieman and Ofer Lahav reflect on DES References Part I: Building the Dark Energy Survey Chapter 1: Early Days of the Dark Energy Survey 1.1 Planning a future for the Blanco Telescope 1.2 An instrument partner for the Blanco 1.2.1 Think what we could do with a camera like that! 1.3 The Dark Energy Survey collaboration comes together, 2003 to 2004 1.3.1 Preliminary allocation of responsibilities 1.3.2 Visit to KPNO 1.3.3 Announcement of Opportunity 1.3.4 DES workshop at Fermilab 1.3.5 Presenting DES to the Program Advisory Committee 1.4 The NOAO proposal for DES 1.4.1 Temple review 1.4.2 Blanco Instrumentation Review Panel review 1.4.3 Memorandum of Understanding 1.5 Presenting DES to the scientific advisory committees 1.6 Building the DES collaboration 1.6.1 The United Kingdom joins the DES collaboration 1.6.2 Spain joins the DES collaboration 1.6.3 The wider DES collaboration 1.7 The DOE–NSF proposal for DES 1.8 Funding DES Chapter 2: The Dark Energy Camera 2.1 DECam (Brenna Flaugher, Fermilab) 2.1.1 Rising from the ashes: 2003 to 2008 2.1.2 Staying afloat: 2008 to 2010 2.1.3 Wrapping it up: 2010 to 2012 2.2 The Optical Corrector (Peter Doel, UCL) Reference Chapter 3: Installation and First Light 3.1 Installation and First Light (Tim Abbott, Cerro Tololo Inter-American Observatory) 3.2 The path to First Light (H. Thomas Diehl, Fermilab) 3.2.1 Preparations off the Blanco Telescope 3.2.2 Preparations on the Blanco Telescope 3.3 First Light! (Alistair Walker, CTIO) Chapter 4: Commissioning t he Dark Energy Camera on the Blanco Telescope 4.1 Commissioning 4.2 The days and nights following First Light 4.3 Donuts at DECam 4.4 The transition to SV Chapter 5: The Dark Energy Survey Early Observations and Science Verification 5.1 Getting in gear 5.2 The SV plan 5.3 The ‘eyeball squad’ 5.4 Early SV phase 5.5 The SV phase is extended 5.6 SV results and accomplishments 5.7 The impact of SV data Reference Chapter 6: DES as a Big Data Machine Part I: The Dark Energy Survey Data Management System 6.1 What is the Dark Energy Survey Data Management? 6.2 Early DESDM 6.3 Intermediate development of DESDM 6.3.1 Splitting up the pipelines 6.3.2 A stronger storage solution 6.3.3 Realistic test data for the community pipeline 6.3.4 Taming hostile codes 6.4 DESDM at present and looking to the future Chapter 7: DES as a Big Data Machine Part II: Source Extractor and the Dark Energy Survey Science Portal 7.1 Analyzing large data sets: The Dark Energy Survey Science Portal solution (Luiz da Costa and Angelo Fausti) 7.1.1 Monitoring the quality of the raw data with Quick Reduce 7.1.2 Exploration of DES processed data 7.1.3 End-to-end processing 7.2 SExtractor and image analysis (Emmanuel Bertin) 7.2.1 SExtractor 7.2.2 Image stacking 7.2.3 Moving to multi-exposure image analysis 7.2.4 Improving deblending and the road ahead References Chapter 8: The Dark Energy Survey Strategy and Calibration 8.1 Constituent surveys within the Dark Energy Survey 8.2 Wide survey 8.2.1 Depth, exposures and image quality 8.2.2 Hexes and tilings 8.2.3 Footprint 8.2.4 Quality cuts 8.3 Time-domain survey 8.4 Schedule 8.5 Tactics 8.6 Photometric calibration Part II: Dark Energy Science Chapter 9: Type Ia Supernovae 9.1 Introduction to supernovae 9.1.1 Types of SN 9.1.2 Superluminous SN 9.2 Cosmology from SN 9.3 Strategy for SN observing with DECam 9.3.1 SN simulations 9.3.2 SN pipeline 9.4 Spectroscopic follow-up of SN 9.5 Year 3 unblinding References Chapter 10: Large-Scale Structure of the Universe 10.1 Introduction 10.2 Large-scale structure of the universe 10.3 Baryon acoustic oscillations 10.4 Measuring large-scale structure 10.5 Large-scale structure in DES 10.6 Baryon acoustic oscillations in DES 10.7 Looking to the future References Chapter 11: Weak Gravitational Lensing 11.1 Introduction 11.2 Weak gravitational lensing 11.3 Weak lensing and dark energy 11.4 Three regimes of weak lensing 11.5 Systematic uncertainties 11.6 From observations to cosmology 11.7 Weak lensing in DES 11.8 DES Year 1 weak lensing catalogues 11.9 DES Year 1 weak lensing mass map 11.10 Looking to the future References Chapter 12: Galaxy Clusters 12.1 Galaxy clusters 12.2 Cosmology from galaxy clusters 12.3 Galaxy clusters in DES 12.4 Measuring cluster mass 12.4.1 X-ray emission 12.4.2 The Sunyaev-Zel’dovich effect 12.5 Clusters beyond cosmology Reference Chapter 13: Theory and Combined Probes 13.1 From data to knowledge 13.2 Introducing the 3 × 2pt correlation function 13.2.1 Galaxy clustering 13.2.2 Galaxy–galaxy lensing 13.2.3 Cosmic shear 13.2.4 Three is the magic number – 3 × 2pt 13.3 Models, parameters and nuisance 13.4 Covariance 13.4.1 Enter the matrix 13.4.2 Two heads are better than one 13.5 Blinding 13.6 DESY1 3 × 2pt results 13.7 Beyond 3 × 2pt 13.8 Coming soon References Chapter 14: Spectroscopic Redshifts 14.1 Spectroscopic redshift 14.2 Spectroscopic redshifts in DES 14.3 OzDES Chapter 15: Photometric Redshifts 15.1 Measuring photometric redshifts 15.2 Validating photometric redshifts 15.2.1 Validation from COSMOS 15.2.2 Validation from cross-correlation 15.3 Future work References Chapter 16: Simulating the Dark Energy Survey 16.1 Introduction to simulations 16.2 N-body 16.3 Simulations in DES – Of MICE and Buzzards 16.3.1 BUZZARD 16.3.2 MICE (Pablo Fosalba) 16.3.3 HALOGEN – BAO mocks 16.3.4 BALROG (Brian Yanny and Yuanyuan Zhang) 16.4 Using the galaxy catalogue simulations References Part III: Non-Dark Energy Science Chapter 17: Galaxy Evolution 17.1 The Dark Energy Survey – A goldmine for galaxy evolution studies 17.2 Luminosity and stellar mass function 17.3 Galaxy environment 17.4 Evolution of galaxy properties in clusters 17.5 Galaxy biasing 17.6 Galaxy structure and morphology 17.7 Galaxy intrinsic alignments 17.8 Galaxies in the early universe References Chapter 18: Quasars 18.1 Inescapable 18.2 Evolution of quasars 18.3 Enter DES 18.4 The plan 18.5 Reverberation mapping 18.6 Using OzDES 18.7 Discovery 18.8 Future References Chapter 19: Strong Gravitational Lensing 19.1 Strong gravitational lensing 19.2 What can we learn from strong gravitational lensing? 19.3 Strong lensing in DES 19.3.1 Identifying strong lenses 19.3.2 Science! References Chapter 20: Stellar, Milky Way and Local Group Science 20.1 The Milky Way 20.1.1 Brown dwarfs in the galactic disc 20.1.2 Red dwarfs 20.1.3 White dwarfs 20.1.4 Galactic open clusters 20.1.5 Variable stars 20.1.6 Galactic stellar streams 20.2 The Local Group 20.2.1 Local Group globular clusters 20.2.2 Stellar structure at the outskirts of the LMC 20.2.3 Milky Way satellite dwarf galaxies References Chapter 21: Solar System Science 21.1 Introduction 21.2 Near-Earth asteroid of DOOM! 21.3 The working group begins 21.4 A treasure trove of transients 21.5 Finding ‘DeeDee’ 21.6 Planet Nine from outer space 21.7 Going nuts about Caju 21.8 Looking back References Chapter 22: Optical Follow-ups to Gravitational Wave Events 22.1 A long time ago... 22.2 Gravitational waves 101 22.3 Putting the Dark Energy Survey GW team together 22.3.1 Developing the strategy 22.4 GW150914 – This is not a rehearsal 22.5 GW170817 – Discovery 22.5.1 Multi-messenger astrophysics 22.6 Standard siren? 22.7 Looking forward – Reflecting back References Part IV: Reflections and Outlook Chapter 23: An Anthropology Angle: Credit and Uncertainty in the Dark Energy Survey 23.1 Introduction 23.2 Background literature 23.3 Credit and uncertainty: Science and infrastructure 23.4 Uncertainty and credit: Scientific knowledge and social relationships 23.5 Credit and certainty: Truth and mythology 23.6 Conclusion References Chapter 24: A Philosopher’s Look at the Dark Energy Survey: Reflections on the Use of the Bayes Factor in Cosmology 24.1 Introduction 24.2 DES Y1 results 24.3 On the Bayes factor 24.3.1 Context-dependence of standards of evidence along the Jeffreys scale 24.3.2 Relative versus absolute evidential measures 24.3.3 Dimensionality and nested models 24.3.4 Simplifications and sensitivity to priors 24.3.5 The Bartlett paradox and wide priors 24.3.6 The Bayes factor as Occam’s razor? 24.4 Philosophical coda Acknowledgements References Chapter 25: Artists’ Reflections Chapter 26: At the Edge of the Abyss: A Poem for the Dark Energy Survey Chapter 27: The Dark Energy Survey and the Future of Dark Energy 27.1 Past 27.2 Present 27.3 Future References Appendix A: The US Department of Energy Approval Process Appendix B: The Dark Energy Survey Collaboration Meeting Group Photos Index 'The past cultures of astronomy and physics evolved their own distinct personalities. The book describes an important milestone in the history of the unification of the two fields and provides an excellent summary of the methods used to explore one of the greatest mysteries in physics today: dark energy.'Physics TodayThis book is about the Dark Energy Survey, a cosmological experiment designed to investigate the physical nature of dark energy by measuring its effect on the expansion history of the universe and on the growth of large-scale structure. The survey saw first light in 2012, after a decade of planning, and completed observations in 2019. The collaboration designed and built a 570-megapixel camera and installed it on the four-metre Blanco telescope at the Cerro Tololo Inter-American Observatory in the Chilean Andes. The survey data yielded a three-dimensional map of over 300 million galaxies and a catalogue of thousands of supernovae. Analysis of the early data has confirmed remarkably accurately the model of cold dark matter and a cosmological constant. The survey has also offered new insights into galaxies, supernovae, stellar evolution, solar system objects and the nature of gravitational wave events.A project of this scale required the long-term commitment of hundreds of scientists from institutions all over the world. The chapters in the first three sections of the book were either written by these scientists or based on interviews with them. These chapters explain, for a non-specialist reader, the science analysis involved. They also describe how the project was conceived, and chronicle some of the many and diverse challenges involved in advancing our understanding of the universe. The final section is trans-disciplinary, including inputs from a philosopher, an anthropologist, visual artists and a poet. Scientific collaborations are human endeavours and the book aims to convey a sense of the wider context within which science comes about.This book is addressed to scientists, decision makers, social scientists and engineers, as well as to anyone with an interest in contemporary cosmology and astrophysics.Related Link(s) "This book is about the Dark Energy Survey, a cosmological experiment designed to investigate the physical nature of dark energy by measuring its effect on the expansion history of the universe and on the growth of large-scale structure. The survey saw first light in 2012, after a decade of planning, and completed observations in 2019. The collaboration designed and built a 570-megapixel camera and installed it on the four-metre Blanco telescope at the Cerro Tololo Inter-American Observatory in the Chilean Andes. The survey data yielded a three-dimensional map of over 300 million galaxies and a catalogue of thousands of supernovae. Analysis of the early data has confirmed remarkably accurately the model of cold dark matter and a cosmological constant. The survey has also offered new insights into galaxies, supernovae, stellar evolution, solar system objects and the nature of gravitational wave events. A project of this scale required the long-term commitment of hundreds of scientists from institutions all over the world. The chapters in the first three sections of the book were either written by these scientists or based on interviews with them. These chapters explain, for a non-specialist reader, the science analysis involved. They also describe how the project was conceived, and chronicle some of the many and diverse challenges involved in advancing our understanding of the universe. The final section is trans-disciplinary, including inputs from a philosopher, an anthropologist, visual artists and a poet. Scientific collaborations are human endeavours and the book aims to convey a sense of the wider context within which science comes about. This book is addressed to scientists, decision makers, social scientists and engineers, as well as to anyone with an interest in contemporary cosmology and astrophysics"--Publisher's website