Dr. Britt Reichborn-Kjennerud is awarded an NSF Astronomy and Astrophysics Postdoctoral Fellowship to carry out a program of research and education at Columbia University. Contemporary and future experiments that measure cosmic microwave background (CMB) polarization anisotropies hold the promise of providing an unprecedented understanding of the origin, composition and dynamics of the universe, as well as possibly the strongest evidence yet supporting inflation theory. To push forward the design of a cutting-edge CMB polarization experiment, Dr. Reichborn-Kjennerud will lead an initiative to characterize the next generation of polarization-sensitive bolometric detectors in a new dedicated testing facility at Columbia University. Dr. Reichborn-Kjennerud will also play a key role in the Antarctic flight campaign and data analysis of the E and B Experiment (EBEX), a leading CMB polarization instrument. EBEX is unique among its contemporaries in its combination of high-frequency coverage and sensitivity to a wide range of scales; these characteristics will allow EBEX to make unprecedented measurements of the amplitude of the galactic polarized dust foreground, which will play a critical role in the analysis of data from future CMB instruments. Additionally, EBEX will probe both of the yet-undetected CMB polarization B-mode signals that were imprinted during the first fraction of a second of the universe, and at late times due to the lensing of foreground matter.
Dr. Reichborn-Kjennerud will also expand an ongoing summer outreach program for New York City public high school students and teachers into a full-year program that would be replicable at other institutions. During each year of the program, one teacher and two students will join the lab during the summer to complete a hands-on research project and to learn about astrophysics and about the lab and university environments. The EBEX timeline will allow the experiment to act as an ideal platform on which the teachers and students will participate in building experimental hardware and working in scientific teams, and the participants will gain first-hand experience with an experiment as it travels from the lab, to Antarctica, and to the edge of space. Each teacher will work with Dr. Reichborn-Kjennerud to produce an action plan for bringing the research experience back to the classroom through school-year activities such as analysis of science data with students, student visits to the lab, and visits by lab members to the school.
My project entailed developing new technologies and building telescopes to study the cosmic microwave background (CMB). The CMB is microwave light just reaching us now which contains an image of our infant universe when it was about 380,000 years old. My project had three major science goals. First, to build hardware for and provide mentorship and oversight for the testing and flight of the E and B Experiment (EBEX). EBEX is a NASA balloon-borne polarization sensitive telescope that was launched over Antarctica in December of 2012. Eleven days of science data was collected during the flight. The second goal of my project was to performa analysis of data from the EBEX 2012 flight and to oversee data analysis efforts of the EBEX graduate students. In the initial stage covered by this fellowship the data analysis included evaluation of the performance of the instrument as well as transforming various data streams into a clean and convenient format for making maps and power spectra of the data. The third goal of the project was to work in the Miller Lab at Columbia University on testing of new cutting edge microwave detectors and to help to design new experiments and write grant proposals which use these detectors. My project also aimed to provide an authentic research experience for high school teachers and students who joined the lab and undertook a specific project. EBEX was launched in December 2012 and the telescope did successfully collect CMB data. I completed analysis of a variety of aspects of the payload performance: the thermal model, the power system, the telescope motion, and the the performance of the star cameras, instruments which help the EBEX team know the direction the telescope is pointing. Analysis of the EBEX data is still ongoing so no science results are yet available. The Columbia Cosmology group has made great progress in developing new detectors for studying the CMB: Kinetic Inductance Detectors (KIDs) have been used to study some science, but they have not yet been used to study the CMB. They are cheaper, faster and easier to fabricate in large arrays than other candidate detectors that are currently used. Our group has also made significant progress in building a mockup of a superconducting magnetic bearing with a belt-free motor and cryogenic encoder. Our test setup is currently being assembled in the custom vacuum chamber we built. The work completed in this fellowship has resulted in the training of graduate students and lab technicians in building hardware and writing software both for instrument control and data analysis. Additionally, during my fellowship both myself and members of the lab made a significant impact on students and a teacher from the New York City School of the Future (SOF). We have hosted the teacher and students in the lab to complete hardware and software projects and visited the school to teach computer programming and about the life of an Astrophysicist. We have exposed these students to a completely different view of science, and made a significant impact on how the teacher approaches teaching science.
