CAREER: Measuring the Spectrum of the Cosmic Microwave Background Anisotropy on Angular Scales from 0.15 to 4 Degrees

点击翻译按钮获取中文摘要

9732960 Devlin The main scientific goal of the research is to the study the anisotropy of the Cosmic Microwave Background (CMB) radiation. The CMB is the photon remnant of the Big Bang. The observations of the fluctuations in light intensity of the CMB, and by analyzing the data, the fluctuations in the matter density of the universe at roughly 100,000 years after the big bang can be inferred and this information used to predict the present distribution of matter in the universe. The anisotropy in the CMB provides a key test of models of structure formation of the Universe. The knowledge of the sizes of fluctuations on different angular scales may allow the measurements of cosmological parameters such as the mass density of the universe, the expansion rate, and the baryon density. These parameters will enable us to learn about the universe today, its past, and its future evolution. The focus of the research is an aggressive plan to produce new results in CMB research. The plan is to combine the best aspects of ground-based and balloon borne experiments. The plan is to measure the spectrum of the anisotropy of the CMB on angular scales of from 0.15 to 4 minutes of arc with unprecedented accuracy. The technique of using ground-based observations has already been proven with previous measurements made in Saskatoon, Canada.. These measurements have very long integration times, but are limited by the poor stability of the atmosphere at the site. Balloon borne observations have negligible atmospheric interference, but are limited by integration time. A telescope built for a balloon measurements has been converted into the Mobile Anisotropy Telescope (MAT) which will be used to make observations from a high plateau (5,200 m) in Chile. The atmosphere is stable at this site and integration times can be extended for as long as necessary. The improvement in the measurements will require the use of state-of-the-art detector technology. A 115 element array of transition edge superc onducting bolometric detectors operating at 300 mK will be built for use with the MAT telescope. The array will to used to collect data which will yield independent measurements of the CMB anisotropy over a large fraction of the sky. The net result will be an improvement over the sensitivity of the Saskatoon data by an order of magnitude or more, and an increase in angular resolution by a factor of three. The other goals are to establish a new laboratory for (CMB) research, to develop a research program that incorporates undergraduates and graduates, and to play a central role in developing an astrophysics curriculum. The curriculum will range from courses for general undergraduates and astronomy/astrophysics majors to courses for graduate students. Major progress has already been made along each of these directions. Data on the CMB with a balloon borne telescope has been obtained. Undergraduates will be able to use a newly established laboratory. The undergraduate students will come from a variety of backgrounds, including physics, mechanical engineering and computer science. The development of a new astronomy course for non-majors will be exciting and instructive for both the faculty and students. The plan is to extend the scope of the research and education activities by initiating an outreach program with the City of Philadelphia high schools which will provide area students with supervised projects in observational astronomy. ***