Dr. David Spergel (Princeton University) will use archival measurements of optical dust polarization to 2000 stars in the galactic halo to generate a polarization template map for microwave background studies. Because polarized millimeter and sub-millimeter emission from dust grains is the dominant foreground for cosmic microwave background (CMB) polarization studies, this template will be essential for efforts to detect primordial gravitational waves. The dust polarization measurements will also be used to study the properties of dust grains, to measure the amplitude and spectrum of magnetic field turbulence in the galactic disk and to fix the zero-point of the dust extinction maps.
The dust polarization measurements will help cosmologists working to detect primordial gravitational waves. These gravitational waves were produced during the first moments of the big bang. Their detection would be of broad interest to both scientists and the general public. This research program will lead to the release of dust template maps that will be widely used by many polarization experiments now under development. The improved measurements of the zero-point in dust extinction maps would be widely used in extragalactic studies. This research program will also train undergraduate and graduate students. By engaging students in substantive research, the program will help to develop the next generation of U.S. scientists.
