Emeriti Faculty

Welch cropped

William (Jack) Welch

Professor Emeritus of Astronomy, Electrical Engineering and Computer Sciences

605U Campbell Hall


Specialty areas

Allen telescope array,Dark dust clouds,Formation of stars,Michelson interferometer array.

Research Interests

In collaboration with other researchers and students in the Radio Astronomy Laboratory and Astronomers at the Universities of Maryland and Illinois, we have developed a Michelson Interferometer Array for millimeter wavelengths at the Hat Creek Radio Observatory of the University of California, located near Mt. Lassen in the northern part of the state. This instrument can form high-resolution images with good spectral coverage of regions of star formation. What we "see" is radiation emitted by trace chemicals in each dust cloud: HCN, CO, etc. The pictures show remarkable objects and processes such as energetic winds and outflows ejected from protostars and massive, rapidly rotating gas clouds with disk shape that are probably the early stages of star clusters. This instrument has operated as the Berkeley Maryland Illinois Association Millimeter Array since 1988. At the present time, this instrument is being combined with a similar array at Caltech which will be located at Cedar Flats in the Into Mountains of southern California. The new combined instrument will be known as CARMA. A new activity at the Hat Creek Observatory in which I am involved is the development of a novel large centimeter wavelength radio telescope, the Allen Telescope Array. This instrument, a joint project with the SETI Institute in Mountain View, will carry out sensitive studies of the ISM and the distant universe, as well as searches for technological evidence of complex life on other planets.