Measurements of X-ray Selected AGN and Novel Superconducting X-ray Detectors Thesis by Megan E. Eckart In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy California Institute of Technology Pasadena, California 2007 (Defended May 22, 2007) ii c 2007 Megan E. Eckart All Rights Reserved iii Acknowledgements First and foremost, I would like to thank my parents, Mark and Judy Eckart, and my sister, Janet; their importance in my life is immeasurable. I would also like to warmly thank my extended family for their love and support. The SEXSI survey not only provided opportunities to use a variety of world class tele- scopes, but allowed me to learn from and collaborate with a great group of people. My advisor, Fiona Harrison, led the project and took a lead role in the X-ray data reduction and analysis. I thank Fiona for her work on SEXSI as well as for her unwavering support and advice; she was extremely helpful and generous with her time, especially as I prepared my thesis. David Helfand offered guidance and support throughout my graduate career, for which I am deeply grateful. His input from across the country as well as his frequent visits to Caltech made the project what it is today. I should mention here, for the record, that it was David and Fiona who crafted our project name (with the lovely acronym). Daniel Stern has played a key role as an expert in the optical and mid-infrared observing and anal- yses, and I thank him for teaching me about spectral reductions and classifications, among many other things. I also especially thank Dan for his support during the final stages of my thesis writing. As the first graduate student on SEXSI, Peter Mao was instrumental both in starting the project and in much of the optical followup effort. I thank Pedro for his many contributions to the survey and for showing me the ropes. I am so glad that we remained good friends after he graduated and left Caltech. Also, I thank James Chakan, who assisted in the X-ray data analysis, Elise Laird, who was crucial to the optical imaging effort, Sarah Yost, who was responsible for the DEIMOS spectral reductions, and Luke Kotredes, who contributed greatly to the Spitzer data analysis. Without the contributions from these colleagues, the first part of my thesis would not have been possible. Finally, I would like to thank the scientists, engineers, and staff who built and operate the telescopes and instruments employed by the SEXSI program. I especially thank the teams responsible iv for the Chandra, Keck, Palomar, and Spitzer observatories. I’m grateful to have had the opportunity to work with the Caltech/JPL microwave kinetic inductance detector group for the final few years of my time at Caltech. First I thank Jonas Zmuidzinas for introducing me to MKIDs and for his patient and inspiring discussions. Bruce Bumble, Sunil Golwala, and Benjamin Mazin were my primary colleagues on the strip detector work that is described in the second part of this thesis. I thank Bruce for his skilled and persistent fabrication efforts that produced the majority of the devices presented in this thesis. Ben and I spent countless hours in the lab together, and I thank him for both his companionship and for introducing me to many aspects of the laboratory work and data analysis. Sunil played a valuable advisory role and I thank him for teaching me a great deal about data analysis and device physics. I thank Peter Mason for teaching me about cryogenics involved in the project, Peter Day for his efforts in helping me to understand the operating principles of the detectors, and Rick LeDuc for sharing his vast knowledge of device fabrication. Last but definitely not least, I thank my fellow graduate students: Jiansong Gao, Tasos Vayonakis, and Shwetank Kumar, who have helped me to understand numerous aspects of the lab work and detector physics. Another important group that I would like to thank consists of Fiona, Sunil, Re’em Sari, and Chuck Steidel, who served as both my candidacy and thesis defense committees. They showed interest in my work and provided crucial feedback. I would also like to recognize the entire Space Radiation Laboratory staff for their friendly support and scientific guidance; in particular, a handful of SRLers have been espe- cially significant in my time at Caltech. My long-time officemate, Brad Cenko, has been a fantastic presence in my life for the past 5 years, and I thank him for his friendship. My days were always interesting during the period when Dae-Sik Moon was a postdoc down the hall – each morning I never knew whether Dae-Sik would taunt me with his signature “Watch your back!,” or provide me with his warm support and advice. SRL has not been the same since he left. Another long-time officemate during earlier years was fellow gradu- ate student Hubert Chen. I thank Hubert for many interesting discussions and for always lending a helping hand when needed. Postdocs Wayne Baumgartner and Mike Muno have provided me with numerous amusing lunchtime discussions as well as valuable guidance. I am grateful that my time at Caltech has allowed me to become friends with many of my fellow physics students: I have enjoyed the many hours spent with Mike Armen, v Parsa Bonderson, Nathan Lundblad, Dave Sand, John Stockton, and Ian Swanson. Parsa Bonderson deserves special mention, as he has been a wonderful friend for every day of my tenure at Caltech, from orientation through our defenses, which commenced a mere 29 hours apart. I thank Donna Driscoll, the Physics Graduate Coordinator, who has been extremely helpful and has always had an open door when I’ve needed assistance. I also appreciate the friendship of fellow Caltech graduate students Serena Guarnaschelli, Tobias Kippenberg, Julie Liu, Melissa Enoch, Cecily Ryan, and Mary Laura Lind. Kevin McHale has been a true friend and a superb companion over the past couple of years, and I cannot thank him enough. I am especially grateful for his extremely generous help during the writing of this thesis; I guarantee that without him my thesis would not have been completed on time or in good health. Friendships cultivated off campus have also been crucial to my time at Caltech. Tara Klassen, Talia Starkey and I came together through unlikely connections to become Pasadena running buddies and great friends; I owe them so much for their ceaseless encouragement and for being an inspiration to me. I especially thank Talia for her support during my thesis crunch through her frequent calls and emails, home cooking, beautiful home-grown flowers and stress-relieving trail runs. I also greatly appreciate the friendship of Jim Chonko, Erin (Kelley) Holford, and Deirdre Scripture-Adams. I’m pleased to have stayed close to friends from Livermore and Cal, and I thank them for their support from afar and especially for their visits to Pasadena. In particular I’d like to thank Livermorons Alison Anastasio, Marisa (Daniel) Beck, Christina Coll, Jodi Denton, Jason Dietrich, Cameron Fortner, and Wendy (Robson) Westcamp, and Berkeley comrades Lea Boyd, Antara Basu-Zych, Blake (Likins) Bullock, Steve Dawson, Jenny (Michel) Dixon, Brenda Fletcher, Laura (Zmijewski) Grant, Nicole Izant, Dale Li, Brian Medeiros, Jessica Wellner, and Victor Bigvic Wong. Finally, I would like to thank Bruce Macintosh and the scientists at the Institute of Geo- physics and Planetary Physics at LLNL for mentoring me through undergraduate summers spent as a research assistant, as well as my professors at Berkeley and Caltech. The research presented here was supported in part by a NASA Graduate Student Re- search Program Fellowship. vi Abstract Major astrophysical advances typically come through combining new observational ap- proaches with new technologies. This thesis involves work on both fronts, combining obser- vational work using data from the Chandra X-ray Observatory and Keck Observatory, two of the premier telescopes of the current generation, with novel superconducting detector development to further technology for future observatories. The subject of the first part of this thesis is the Serendipitous Extragalactic X-ray Source Identification (SEXSI) program, a survey using Chandra data specifically selected to probe the dominant contributors to the 2 – 10 keV cosmic X-ray background. To accomplish this, SEXSI covers more than 2 deg2 of sky and employs optical photometric and spectroscopic followup of sources discovered in archival Chandra fields. The resulting source sample consists of 1034 hard X-ray-selected sources with R-band optical-followup imaging, and optical spectroscopy for 477 of the sources, primarily from Keck Observatory, filling the gap between wide-area, shallow surveys and the deep, pencil-beam surveys such as the Chandra Deep Fields. The vast majority of the 2 – 10 keV-selected sample are AGN with redshifts between 0.1 and 3. In this thesis we discuss results from our survey, including the spectroscopic properties of hard X-ray sources, the relationship between X-ray and optical properties of our sources, and our sample of spectroscopically-confirmed, narrow- lined, obscured type II quasar candidates. In addition, we present infrared data from the Spitzer Space Telescope that cover a subset of the Chandra fields, which allows us to explore the relative strengths of Chandra and Spitzer as black-hole finders. The second part of this thesis focuses on microwave kinetic inductance detectors (MKIDs), which are an exciting new superconducting detector technology that has breakthrough po- tential for providing megapixel imagers with several eV energy resolution for use in future X-ray missions. These detectors utilize simple, thin-film lithographed microwave resonators as photon detectors in a multiplexed readout approach.