Directed searches for continuous gravitational waves from spinning neutron stars in binary systems by Grant David Meadors Adissertationsubmittedinpartialfulfillment of the requirements for the degree of Doctor of Philosophy (Physics) in The University of Michigan 2014 Doctoral Committee: Professor John Keith Riles, Chair Professor Fred C. Adams Professor Nuria Pilar Calvet Research Scientist Herold Richard Gustafson Professor Timothy A. McKay Professor Stephen C. Rand c Grant David Meadors 2014 ⃝ All Rights Reserved To the tree of Life, which took stardust and evolved into us. Pro arbore Vitae, ex nube stellarum ad nos evolvit. ii ACKNOWLEDGEMENTS Thanks should go beyond a simple page. Lest I forget, let me reflect on all the people without whom I would not have made it here. To my parents, Erin O’Rourke- Meadors and Gregory David Meadors, and my brother, Patrick Thomas Meadors. Home’s name follows you; three decades have we explored – beyond seas, roots grow. My dear grandmother, Florenceann O’Rourke (n´ee Williams), supported my undergraduate studies at Reed College. Aunt Nan & Uncle Bud Williams made book- reading & museum-going fond memories. Hanford gave time to learn my family’s wonderful stories. If only my paternal grandparents, ShulerandJeanne(Brown) Meadors, could be here too. Ethan Obie Romero-Severson is ever a devoted friend in adventures & colleague in mathematics: Team Science for fouryearsandcounting! Keith Riles is a dedicated and conscientious adviser: steadyprogressishownew science is born – detecting gravitational waves is a tricky task, and his thoughtful attention to details will be part of what makes it possible. Dick Gustafson introduced me to the field in 2005 and has helped ever since; my only regret working with him is that we never flew the glider, although we nearly won a sailboat regatta. Evan Goetz pioneered this kind of search: Oregon makes good scientists. Vladimir Dergachev loves the lab: bolshoye spasibo! Best to my office-mates, Jax Sanders & Santiago Caride, on their way soon! Keita Kawabe is a concerted collaborator and experimenter, attentive and dilligent. Chris Messenger ever-patiently organized the data challenge and has a keen eye for the future. Marco Cavaglia orchestrated the iii fun of the World Science Festival exhibition. Mike Landry encouraged me to come for my sojourn at Hanford and, with Fred Raab, made it a welcoming place. Sheila Dwyer and Sheon Chua, helped me see the squeezed light at the end of the beam tube. Conor Mow-LowryandAlexander Khalaidovski, were likewise great squeezer friends. Our excellent operators, Cheryl Vorvick, Gerardo Moreno, Jonathan Berliner and Dani Atkinson, were tireless in reviving H1. Sam Waldman kindly helped us replace the OMC. Lisa Barsotti & Matt Evans and Daniel Sigg made our whole quantum optics experiment possible at Hanford, with Nergis Mavalvala at MIT keeping all running smoothly behind the scenes. Greg Mendell got me started on cluster computing and went far to help me learn about programming in science. Dale Ingram helped me lead my first public LIGO tours. Rana Adhikari & Jenne Driggers are great with filters. Ian Harry & Jess McIver have been invaluable in seeing my feedforward work in the larger world of Detector Characterization. Joey Key gave me a unique venuetopresentthat work too! JeffKissel knows how to wear a bowtie, and talk about servos, with style. Nicol´as Smith-Lefebvre has been there in LIGO since I started nine years ago. May physics interest us all for years to come. To my physics friends at Michigan, one of the most tight-knit cohorts. Michelle Adan, Matt Bales & Amanda Boomer, Kevin Bergemann, Alex Burgers and Bo Zhang, thank you for all having organized our Get-a-Job meetings to get over the final hurdles. Melinda Morang helped me find little brown birds, andmyfriendBeverly Lau from Reed helped me appreciate all animals. Friends are ever in diaspora, but IamfortunatetohavekeptupphilosophywithmyfriendSuzanne Kaufmann over the years. Miriam related myriad facets of life. From Reed, myfriendsGillian Woodruff& Jesse Hallett as well as Carrie Thomas & Evan Pierce included me in iv their weddings – congratulations on your little ones! – and Dash Vitullo’s perspective (and particle accelerator tour) anchored me. Reed’s professors in Portland helped launch me to Michigan. Robert Reynolds advised my undergraduate thesis and showed how really to use atelescope.David Griffiths filled many students, including me, with enthusiasm for physics that lasts to this day. Johnny Powell always had sound advice. Joel Franklin helped me appreciate what gravitational waves meant. Tom Wieting almost converted me to mathematics with his inimitable style of geometry. Ginny Hancock has a sound ear for music and life’s many challenges. Directing the Reactor, Stephen Frantz and Rachel Barnett created the critical conditions for practicing science and meeting dear friends: our elements are fissioned now, but that core made us into new isotopes. Epidemiology compatriots have made Ann Arbor my home: thankstoMeghan Milbrath (follow the bees), Ian Spicknall (thanks for the coffee), Erin Shellman and Bryan Mayer (who read my whole thesis) – everyone in Edit Club is a Doctor now! Psychology teammates, Emily Bonem, Ali Earl, and Stephanie Carpenter, brought me through a long winter: good luck, loose seals. Even the sky is not the limit for my Michigan Flyers instructors, Anthony Sumner and especially (Amelia C.) Jayne. And to my dear friends Aric Knuth of English and James Leija of the University Musical Society, who revitalized a love of literature and art, and who brought me in one Thanksgiving. Thanks I give now again. May my coming endeavor at the Albert Einstein Institute in Hannover help us travel through, and shrink, space and time, just like a gravitational wave. Read on –formorestill,namedwithin,madethisworkareality. This dissertation bears LIGO Document number DCC-P1400102 1. 1For further questions, please contact the author: [email protected] v TABLE OF CONTENTS DEDICATION .......................................... ii ACKNOWLEDGEMENTS .................................. iii LIST OF FIGURES ...................................... x LIST OF TABLES ....................................... xix LIST OF APPENDICES ................................... xx CHAPTER I. Introduction ....................................... 1 II. Gravitational Waves and LIGO ........................... 5 2.1 Cosmic sources of gravitational waves ...................... 5 2.1.1 History from General Relativity .................... 10 2.1.2 Contrast with electromagnetic and particle astronomy ....... 12 2.2 General relativity ................................. 14 2.2.1 Symmetry and action principles .................... 14 2.2.2 Derivation of field equations ...................... 15 2.2.3 Radiation from quadrupoles ...................... 20 2.3 Astrophysical estimates .............................. 23 2.3.1 Sources: burst, continuous, inspiral and stochastic ......... 23 2.3.2 Continuous waves from neutron stars ................. 26 2.4 Laser Interferometer Gravitational-wave Observatories ............ 28 2.4.1 From Weber bars to interferometry .................. 28 2.4.2 Gravitational wave interferometry in theory ............. 29 2.4.3 Interferometer theory in practice ................... 32 2.4.4 Observatory operation ......................... 33 2.5 Detector characterization and development ................... 37 2.5.1 Feedforward filtering .......................... 38 2.5.2 Phase camera .............................. 41 2.5.3 Advanced observatories and beyond .................. 44 2.5.4 Worldwide network ........................... 46 2.6 Summary ...................................... 47 III. Feedforward: Auxiliary MICH-PRC Subtraction ................ 49 3.1 Introduction .................................... 50 3.2 Description of the feedforward method ..................... 52 3.2.1 Auxiliary noise coherence at sensitive frequencies .......... 55 vi 3.2.2 Estimating filters ............................ 56 3.3 Feedforward in- and out-of-loop methods .................... 61 3.3.1 Manually designed rational filtering in-loop ............. 62 3.3.2 Frequency-domain automated filter design .............. 62 3.3.3 Wiener filters .............................. 64 3.3.4 Prospects for near-real-time filtering ................. 64 3.4 Safeguard and veto methods ........................... 65 3.4.1 Calibration integrity .......................... 65 3.4.2 Runtime safeguards ........................... 66 3.4.3 Post-processing safeguards ....................... 67 3.5 Feedforward with MICH and PRC channels ................... 69 3.5.1 Filter fitting across science segments ................. 72 3.6 Results of feedforward ............................... 75 3.6.1 Post-processing diagnostics ...................... 75 3.6.2 Feedforward benefits and potential .................. 75 3.7 Conclusion ..................................... 83 3.8 Postscript ..................................... 85 IV. Squeezing: Quantum Vacuum Phase Noise .................... 92 4.1 Squeezing theory .................................. 92 4.1.1 Problems with lasers: thermal compensation ............. 93 4.1.2 Quantum shot noise and radiation pressure ............. 94 4.1.3 Squeezing filter cavities ......................... 98 4.2 LIGO Hanford Observatory quantum vacuum squeezing ............ 98 4.2.1 Collaboration and contributions .................... 98 4.2.2 Squeezing’s scientific benefit ......................106 4.3 Squeezing large