2015 Ralph B. Baldwin Award Lecture in Astrophysics and Space Sciences Please join the Department of Physics Tuesday, May 5, 2015 to celebrate Physics Alumnus Dr. Tomasz Biesiadzinski Recipient of the Ralph B. Baldwin Award 4:00 to 5:00 pm in 340 West Hall Reception prior to public lecture at 3:30 pm in 337 West Hall Dr. Biesiadzinski will give a public lecture on his U-M research and discuss his current work at the SLAC National Accelerator Laboratory. Unbiasing Cosmological Surveys Abstract: Large scale observations of the Universe can reveal a great deal about its nature and evolution. They are particularly necessary to study dark energy, the mysterious source that drives the accelerating expansion of the Universe. Among these observations are surveys of galaxies, supernovae and of the millimeter-wave sky. Galaxy and millimeter-wave surveys of the Sunyaev-Zel'dovich (SZ) effect can be used to trace the distribution of matter back through time and how it was influenced by dark energy. Similarly, measurements of distances to supernovae tell us about how the space between them and us changed over time. All of these measurements are made difficult by various physical and instrumental sources of uncertainty and bias. We studied some of these uncertainties in near-infrared instruments for supernovae observations and in the joint analysis of optical galaxy and SZ sources in order to eliminate biases from the measurement of cosmological parameters that describe the Universe. The Ralph B. Baldwin Prize in Astrophysics and Space Sciences is annually awarded to a scholar in the fields of Astronomy, Atmospheric, Oceanic, and Space Science; Chemistry; Physics; or Geology who has received a University of Michigan Ph.D. during the previous year. This award recognizes excellence in research activities pertaining to space, its bodies, and relevant physical processes. Recipients have demonstrated original and significant contributions to their fields as measured in their thesis and scholarly publications. The Ralph B. Baldwin Prize in Astrophysics and Space Sciences is an award sponsored by a generous gift to the University by Dr. Ralph B. Baldwin.