David Williams, adjunct professor of physics at UC Santa Cruz and the Santa Cruz Institute for Particle Physics (SCIPP), and Pascale Garaud, professor of applied mathematics in the Baskin School of Engineering, have been elected Fellows of the American Physical Society (APS) in recognition of their exceptional contributions to physics.
The APS citation for Williams recognizes him "for contributions to the study of gamma rays from extragalactic sources such as gamma-ray bursts and blazars, for using gamma-ray data to test cosmological models of the extragalactic background light, and for leadership in the development of past, present, and future ground-based gamma-ray telescopes."
Williams's research focuses on the study of high-energy gamma rays from astrophysical objects such as supermassive black holes. He is a member of two large collaborations for gamma-ray astronomy: the Very Energetic Radiation Imaging Telescope Array System (VERITAS) in Arizona, and the Cherenkov Telescope Array (CTA), a planned next-generation ground-based observatory for gamma-ray astronomy at very high energies. Williams currently is deputy spokesperson of the VERITAS collaboration and chairs the CTA-US consortium. He is also an affiliated scientist with the Fermi Large Area Telescope (LAT).
Williams is particularly interested in understanding the nature of gamma-ray bursts and the high-energy emission mechanism of active galactic nuclei. He participates in both the development of the instruments for the experiments, especially the electronics and photodetectors, and in the analysis and interpretation of the data.
The APS recognized Garaud "for fundamental contributions to the understanding of astrophysical double diffusion, especially the formation of layers and staircases."
Garaud's research focuses on fluid dynamics and magnetohydrodynamics applied to astrophysics and occasionally geophysics. She specializes in understanding and quantifying mixing processes produced by large-scale fluid flows and magnetic fields, as well as small-scale turbulence. Her work involves a range of applied mathematical tools from numerical experimentation using high-performance computing to pen-and-paper analytical derivations.
Garaud is the founding director of the Kavli Summer Program in Astrophysics. She is also on the faculty of the Geophysical Fluid Dynamics Summer Program at the Woods Hole Oceanographic Institution.
Election as an APS Fellow is a distinct honor signifying recognition by one's professional peers. Each year, elected fellows number no more than one-half of one percent of APS membership. This year, 168 fellows were selected and recognized for their contributions to science. APS represents over 55,000 members, including physicists in academia, national laboratories, and industry in the United States and throughout the world.