2008 Jansky Lecturer: Dr. Arthur M. Wolfe
Associated Universities, Inc. (AUI), and the National Radio Astronomy Observatory have awarded the 2008 Karl G. Jansky Lectureship to Dr. Arthur M. Wolfe of the University of California, San Diego (UCSD). The Jansky Lectureship is an honor established by the trustees of AUI to recognize outstanding contributions to the advancement of radio astronomy.
Abstract:
Most of what we know about high-redshift galaxies comes from light emitted by stars. Yet, at sufficiently large redshifts most of the baryons in galaxies must have been gas. In this talk I describe several investigations of the damped Lyman-alpha absorption systems (DLAs), a population of gas layers that dominates the neutral-gas content of the Universe in the redshift interval z = [0,5] and serves as neutral-gas reservoirs for star formation in early galaxies. I discuss the first efforts to find DLAs through the detection of 21 cm absorption lines toward radio-bright quasars. I then review surveys for DLAs in the optical spectra of background quasars. These have produced surprising results concerning the cosmic evolution of neutral gas, the rate of in situ star formation in early galaxies, and the cosmic evolution of chemical elements. I discuss evidence for bimodality in DLAs and its implications for the bimodal properties of modern galaxies. Finally, I describe the recent GBT detection of Zeeman splitting of a 21 cm absorption line at z = 0.692, and its implications for the generation of magnetic fields at high redshifts.
Dr. Wolfe has made major contributions in several areas of astronomy. Along with Rainer Sachs, he predicted the Sachs-Wolfe Effect, a phenomenon which forms the basis for modern precision cosmology using the background radio emission left over from the Big Bang. In the 1970s, he discovered that light emitted by very distant galaxies is absorbed by hydrogen atoms in previously-undetected intervening gas clouds. From the 1980s until the present, he used optical light emitted by distant quasars to show that these clouds are the progenitors of stars found in modern galaxies. This phenomenon has since been used extensively to study the production of heavy elements and history of star formation in the Universe. He also did landmark research on whether the fundamental constants of nature, such as the charge of the electron and the masses of elementary particles, do, in fact, remain constant through cosmological time.
Dr. Wolfe was the Director of the Center for Astrophysics and Space Sciences at UCSD from 1997 to 2007. He joined UCSD as a Professor of Physics and Astronomy in 1989, leaving the University of Pittsburgh, where he had taught since 1973. He holds the Chancellor's Associates Chair of Physics at UCSD. Dr. Wolfe received his Ph.D from the University of Texas at Austin. He is a Fellow of the American Academy of Arts and Sciences, and received the Sackler Fellowship of the Institute of Astronomy at the University of Cambridge, UK, in 2004.
We are pleased to have a scientist of Dr. Wolfe's stature to carry on the tradition of excellence established by the Jansky family, and look forward with anticipation to his presentation this fall.
The dates and locations for Dr. Wolfe's 2008 Jansky Lectures, titled "Finding the Gas that Makes Galaxies", are as follows:
- Charlottesville - Monday, September 15, 2008, at 7 p.m. in UVA, Gilmer Hall, Room 130, McCormick Road. (View Map)
- Green Bank - Thursday, September 18, 2008, at 7 p.m. in the NRAO Science Center Auditorium.
- Socorro - Friday, October 24, 2008 at 8 p.m. in New Mexico Tech, Workman 101.
Fred K.Y. Lo
NRAO Director
