Justin Albert (University of Victoria), Yorke Brown (Dartmouth College and Harvard University), Christopher Stubbs (Harvard University), Karun Thanjavur (University of Victoria), and Peter Zimmer (Go Green Termite and University of New Mexico)
Keywords: astrophysics, cosmology, photometry, calibration, radiometry, polarimetry, optical, microwave
Abstract:
Deeper understanding of the accelerating expansion of the universe, and the mysterious dark energy that causes it, will require unprecedented photometric precision, as photometry is presently the limiting uncertainty on our knowledge of dark energy and the universe’s resulting acceleration. Laboratory and solar photometry and radiometry regularly achieve precisions on the order of parts in ten thousand, but photometric calibration for non-solar astronomy presently remains stuck at the percent or greater level. We discuss ALTAIR, the project to erase this discrepancy, and the steps to achieving dramatically-improved laboratory-level photometric precision for Pan-STARRS, LSST, and other major astronomical surveys both this decade and next. In particular, we show initial results from the first flights of our NIST-calibrated balloon-borne light source, as well as ground-based and near-field calibration of the source. Our technique is additionally applicable to microwave astronomy. Observation of gravitational waves in the polarized cosmic microwave background will similarly require unprecedented polarimetric and radiometric precision, and we briefly discuss our current development of a calibrated microwave source above the atmosphere as well.
Date of Conference: September 10-13, 2013
Track: Poster