Laird A. Thompson Professor of Astronomy

Galaxies & Cosmology (1974-1987): Early in my career I worked in extragalactic astronomy and concentrated on clusters of galaxies, galaxy morphology, and galaxy redshift surveys. With Prof. Stephen A. Gregory (U. New Mexico) I carried out the first wide-angle redshift survey aimed at mapping the large scale galaxy distribution out to distances of 100 Mpc. Immediately upon mapping the 3D galaxy distribution, we saw for the first time large voids in the galaxy distribution ( (Gregory and Thompson 1978. ApJ vol. 222, p. 784). In our paper we posed a challenge to theoretical cosmologists to explain this completely unanticipated structure. For more details on exactly how the discovery was made, go to the explanation in : Voids and Superclusters. Each successive redshift survey -- CfA, Las Campanas, 2dF, SDSS -- has served to reconfirm the significance of the beautiful & intricate filamentary structure traced by the large scale distribution of galaxies. Iregularities in both the large scal distribution of galaxies and in the Cosmic Background Radiation are now being used to define the fundamental parameters of the emerging standard model of cosmology.

Instrumentation (1982-1990): In the early 1980's I began to work on projects aimed at improving the image quality at ground-based telescopes. My first instrument was a microprocessor controlled tip-tilt system called ISIS which was built at the Institute for Astronomy for use at Mauna Kea Observatory (Thompson and Ryerson 1983, Proc. SPIE, vol.445, p. 560). Following Foy & Labeyrie's suggestion that a laser guide star could be used as the reference source for an adaptive optics (AO) system, I initiated the first effort to project a sodium laser guide star into the mesosphere above Mauna Kea Observatory (Thompson and Gardner 1987, Nature, vol. 328, pg. 229). This was followed by 3 years of intense work with Chester Gardner and his students in the Univ. of Illinois Electrical and Computer Engineering Dept. to define many of the pioneering aspects of laser guided AO systems. Unknown to us, a parallel laser guided AO development effort was underway by the U.S. Air Force. How our work helped to trigger the declassification of this Top Secret research is described in the section AO History. In the last 15 years adaptive optics technology has figuratively "exploded" and has made it possible to do from ground-based telescopes what was previously possible only from space. Adaptive optics technology is now transforming the way astronomers plan and design the next generation of giant telescopes.

Adaptive Optics Work (1990 - present): In 1990 I obtained funds from the National Science Foundation to begin experiments with Rayleigh scattered UV laser guide stars. These experiments with a 35 Watt Excimer laser led directly into my Mt. Wilson laser guided AO system called UnISIS. Unlike most other AO systems on giant telescopes, UnISIS has an open and flexible design. It is laid out on a large optical bench at the Coude focus of the Mt. Wilson 2.5-m telescope. UnISIS has both laser guide star and natural guide star AO capabilities. Two science cameras allow images to be taken simultaneously at visual and at near-IR wavelengths. On the right is an image of a star taken with UnISIS at 2.12 microns (Ks-band) with a Strehl ratio of 0.67.

Postdocs Past & Present	Grad Students Past & Present	Other Links
Paul Eskridge 1987-1989	Christopher Neyman 2002	Contact Information
Peter McCullough 1993-1995	Michelle Griffin 2003	Teaching
Robert Gruendl 2002-2004	Samuel Crawford	Academic Biographical Information
Abhijit Chakraborty 2004-2006		Personal Highlights