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Using the Cosmic Microwave Background to Probe Structure at Intermediate Redshift

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Using the Cosmic Microwave Background to Probe Structure at Intermediate Redshift ILLUMINATING THE UNIVERSE: USING THE COSMIC MICROWAVE BACKGROUND TO PROBE STRUCTURE AT INTERMEDIATE REDSHIFT A DISSERTATION SUBMITTED TO THE DEPARTMENT OF PHYSICS AND THE COMMITTEE ON GRADUATE STUDIES OF STANFORD UNIVERSITY IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY Stephen John Osborne June 2013 © 2013 by Stephen John Osborne. All Rights Reserved. Re-distributed by Stanford University under license with the author. This dissertation is online at: http://purl.stanford.edu/sz245wk1516 ii I certify that I have read this dissertation and that, in my opinion, it is fully adequate in scope and quality as a dissertation for the degree of Doctor of Philosophy. Sarah Church, Primary Adviser I certify that I have read this dissertation and that, in my opinion, it is fully adequate in scope and quality as a dissertation for the degree of Doctor of Philosophy. Steven Allen I certify that I have read this dissertation and that, in my opinion, it is fully adequate in scope and quality as a dissertation for the degree of Doctor of Philosophy. Chao-Lin Kuo Approved for the Stanford University Committee on Graduate Studies. Patricia J. Gumport, Vice Provost Graduate Education This signature page was generated electronically upon submission of this dissertation in electronic format. An original signed hard copy of the signature page is on file in University Archives. iii iv Abstract The cosmic microwave background (CMB) provides a backlight that allows us to probe structure out to the last scattering surface. We exploit observations of the sky at microwave and sub-mm wavelengths to measure properties of galaxies and galaxy clusters, as well as to search for possible pre-inflationary signals. In Chapters 2–4 we measure the correla- tion between the dark matter distribution and the microwave and sub-mm emission from galaxies to probe the connection between dark and luminous matter at redshifts 1 3. ⇠ − CMB photons are gravitationally deflected by dark matter overdensities, with the majority of the 3 arcminute RMS deflection occurring between redshift 2 and 3. The dark matter ⇠ structures that lens the CMB are traced by dusty star-forming galaxies that emit strongly in the infrared, and have a redshift distribution that peaks between redshift 1 and 3. We use observations of the CMB from the Planck satellite to reconstruct the deflection angles with statistical estimators, and we correlate the deflections with observations of the infrared background light at 100-850 GHz. We find that the two signals are strongly correlated, with a correlation coefficient of approximately 0.8, and we use the measured cross spectrum to estimate the minimum mass scale at which dark matter halos host a CIB source, as well as the star formation rate density in three redshift bins between redshift 1 and 7. In Chapter 5 we use the Doppler shift of CMB light scattered by moving galaxy clusters, known as the kinetic Sunyaev-Zeldovich (kSZ) e↵ect, to put a limit on the large-scale velocity distri- bution of a sample of galaxy clusters observed in WMAP CMB data. On 100 Mpc scales cluster velocities relative to the CMB are expected to be small, originating from gravita- tional instabilities. Larger motions could be generated by pre-inflationary inhomogeneities that leave a “tilt” across our horizon, resulting in a uniform matter flow across the horizon. The kSZ e↵ect is sensitive to such a flow, and we use it to constrain the radial and dipole v velocity of a sample of 736 clusters with mean redshift 0.12, finding no evidence for either. In Chapters 6 and 7 we search for a possible pre-inflationary signal in CMB data. Mod- els of inflation suggest that our current patch of the universe could have been created as a nucleation bubble from a phase of false vacuum eternal inflation. If additional bubbles are produced, then it is possible that one of them intersected our past lightcone at the time of decoupling, imprinting a disk-shaped signal in the CMB. We have searched for this signal in the WMAP data using optimal algorithms that evaluate the exact posterior likelihood in an efficient and computationally fast way. We find no evidence for the signal, and place limits on the curvature perturbation generated by a collision intersecting the last scattering surface. vi Preface Each chapter in this thesis, with the exception of the introduction and conclusion, is a complete paper, and was written in collaboration with others. Some of the papers are in the process of journal submission, and the final versions may di↵er from those presented here. The formatting has been changed for consistency between chapters, and additional sections have been added to Chapter 2 to provide background information. The work was done in collaboration, and I will now outline the contributions that I made. Several of the results use data from the Planck satellite, which is a European Space Agency experiment, with a significant NASA contribution, designed to measure CMB tem- perature and polarization anisotropies. The project grew from two proposed missions, the cosmic background radiation anisotropy satellite (COBRAS) and the satellite for measure- ment of background anisotropies (SAMBA), which were combined and selected as the 3rd Medium-sized mission in the Horizon 2000 Scientific Programme. The success of the mis- sion and the high quality of the data are due to the combined e↵ort of a large team of scientists and engineers. I am a member of the Core Team of scientists on the High Fre- quency Instrument (HFI), one of two instruments onboard Planck (the other being the Low Frequency Instrument) and I joined the project after the satellite had been constructed. I was involved in the pre-flight testing of the instrument, analyzing data from tests done at Centre Spatial de Liege` with Jean-Michel Lamarre. I worked with Andrew Lange’s group at Caltech and the Planck group at JPL on several aspects of the low-level data processing. My main contribution was to better determine the HFI detector time response, by analyzing data from tests where the detector bias current was stepped, and by comparing scans of the Galaxy made six months apart. These projects were done in collaboration with Brendan Crill and Guillaume Patanchon. vii The analysis presented in Chapter 2 was developed over many iterations between my- self and Duncan Hanson, with Olivier Dore´ providing valuable comments, suggestions, and guidance. The paper presented in Chapter 3 is one of the Planck Collaboration papers, and as such represents the work of many people. I made significant contributions to all aspects of the analysis directly related to the work in Chapter 3, including the measure- ment, null tests, and modeling sections. The project was initiated, proposed, and lead by Olivier, who contributed to all aspects of the paper. Ultimately, the lens reconstructions used in the analysis were produced by Duncan; although I made my own reconstructions, we used Duncan’s to be consistent with the Planck lensing power spectrum paper. In addi- tion, Duncan generated the simulations necessary to calculate the estimator normalization 1 and mean-field, and developed and implemented the C− pipeline. I performed the cal- culations in the modeling section, however the code to calculate the CIB auto and cross power spectra with the halo model was given to me by Olivier. The work in Chapter 4 is an extension of the modeling work in Chapter 3 and was done with Olivier. Chapter 5 is largely my own work. I wrote the code and performed the analysis, while Sarah Church, Elena Pierpaoli, and Daisy Mak provided valuable comments and sugges- tions. Many of the results were checked by Daisy who developed an independent analysis pipeline. Chapters 6 and 7 were written in collaboration with Leonardo Senatore and Kendrick Smith. The algorithms were developed in collaboration, and it is difficult to separate in- dividual contributions. The theoretical background was largely written by Leonardo, and the frequentist analysis was primarily developed by Kendrick. I wrote the code, with the 1 exception of the C− function and the code to calculate the bubble profiles smoothed by the CMB transfer function, both of which were written by Kendrick. viii Acknowledgments Without the help, advice, and encouragement of many people this work would not have been successfully completed. The main person I have to thank is my advisor, Sarah Church, who has supported me throughout, providing advice and assistance, and ensuring that I always had funding to pursue interesting research ideas. Thanks to Sarah, I was able to participate in several observing runs, first to Mauna Kea with the SuZIE experiment, and later to Chile with the QUIET telescope. I am grateful to Charles Lawrence for letting me join the Planck Collaboration and allowing me to work at JPL for extended periods of time, and to Andrew Lange who let me work with his group at Caltech when I first joined the Planck team. I owe a huge amount to Olivier Dore,´ who advised me on all aspects of research, helping me to fully participate in the Planck scientific analysis and introducing me to several of his collaborators. It was a pleasure writing papers, proposals, and presentations with Olivier, and I learned a lot about galaxies, star formation, and the infrared background. I visited Caltech and JPL many times to meet with Olivier, and every trip was engaging. I enjoyed working with Duncan Hanson on the Planck lensing analysis and learning about statistical estimators, and am grateful for the significant amount of time he has spent answering my— often trivial—questions. It was always entertaining visiting Duncan at Caltech and taking his dog on walks.
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