Exploring the origin and fate of the universe with millimeter-wave and radio instrumentation and observations

点击翻译按钮获取中文摘要

The proposed research program develops technology and uses direct astrophysical measurements to shed light on the origin, fate, and composition of the universe.With the South Pole Telescope, we recently made the first detection of the faint B-mode component of the cosmic microwave background (CMB) radiation. B-modes encode information about the mass distribution over the entire observable universe through gravitational lensing and may eventually allow us to detect gravity waves emanating from early universe inflation--a holy grail for observational cosmology. With data from the upcoming 3 year observing period, we will reach map depths that allow us to accurately characterize the polarization signal and detect or place exciting new limits on gravity waves from inflation. In addition, we are developing a next generation SPT polarimeter, for which will be building and deploying a new readout system that enables an order of magnitude larger focal plane.The Canadian Hydrogen Intensity Mapping Experiment (CHIME) is a novel new radio telescope that will map the largest volume of the universe observed to date and may unlock the mysteries of Dark Energy. Our group played a key role in developing the CHIME concept, demonstrating its feasibility, and obtaining funding for the telescope construction. CHIME will use 21 cm emission from neutral hydrogen as a tracer of the matter distribution in the universe, allowing us to measure the apparent scale of the tiny Baryon Acoustic Oscillation (BAO) anisotropy as a function of redshift. CHIME is designed to observe the key epoch when the universe was 1/5 to 1/2 of its present age (redshift z=0.8 to 2.5) and the expansion of the Universe transitioned from decelerating to accelerating, driven by Dark Energy.Using the BAO as a standard ruler, we will measure the expansion history of the universe and provide a new window which may potentially unlock the physics of Dark Energy. As a full-scale digital radio telescope with no moving parts, CHIME is also an entirely new telescope paradigm for radio astronomy surveys. Building on my group's successes in CMB instrumentation and analysis, we are at the core of the CHIME instrument design and realization, taking responsibility for the GHz digitizers and FPGA-based correlator. The activities which will be undertaken in this grant period are:(1) Develop and commission CHIME to make the best measurement of Baryon Acoustic Oscillations at redshift 1 to 2.5, placing new constraints on Dark Energy. Pioneer the correlator instrumentation techniques, calibration, observing strategy and data analysis for cylindrical digital radio telescopes.(2) Analyze new data from the South Pole Telescope polarimeter (SPTpol), with a focus on the B-mode component of the CMB polarization where the gravitational lensing signal dominates and inflationary gravity waves may be detectable. Build on our group's cluster cosmology experience to use Sunyaev Zel'dovich selected galaxy clusters from the SPT-SZ and deep SPTpol temperature fields to study the growth of structure in the universe.(3) Develop the next generation of bolometer readout systems for new experiments including the South Pole Telescope 3rd generation receiver, the Simons Array telescopes, and future satellite-based mm-wavelength telescopes.My group has earned an international reputation for driving advances in instrumentation that enable new cosmology measurements. Group members, which include astronomers, physicists and engineers, have led key science papers resulting from the instruments we've built. We collaborate frequently with industrial partners and spin-off technology has been used by many researchers internationally.