Department of Astronomy
Lewis E. Snyder
Professor
Ph.D., Michigan State, 1967
snyder@astro.uiuc.edu
For many years, my colleagues and I have used radio spectroscopy to
discover and identify several new interstellar molecular species:
formaldehyde (H2CO), hydrogen cyanide (HCN), hydrogen isocyanide
(HNC), the formyl ion (HCO+), the formyl radical (HCO), nitroxyl
(HNO), isocyanic acid (HNCO), sulfur dioxide (SO2), dimethyl ether
((CH3)2O), methyldiacetylene (CH3C4H), and methylcyanodiacetylene
(CH3C5N). Today, many of these interstellar molecules are used
routinely for probing star formation in our galaxy and in other
galaxies. Our circum- stellar observations have resulted in the first
detection of the SiO maser, the first statistically significant
determination of the shell size of an OH maser star, IRC + 10011, and
the confirmation of circumstellar SiC2, a ring molecule. Early
cometary observations using the 120 ft. telescope of the Vermilion
River Observatory produced a series of cometary OH maser emission
detections starting with the detection of Comet West. Other important
cometary results include the first detection of cometary HCN, the
first radio image of a comet, and the detection of cometary
formaldehyde.
Current research interests include using the BIMA Array to study
maser excitation in both circumstellar shells and in regions of star
formation, the VLA at centimeter wavelengths to detect and map
molecular species in comets, and searches for interstellar molecules
of potential prebiotic importance.
Selected Publications:
Microwave Detection of Interstellar Formaldehyde. Snyder, L.E., Buhl,
D., Zuckerman, B., and Palmer, P. Phys. Rev. Lett. 22, 679, 1969.
Observational Characteristics of Masers Associated with Stars. Snyder,
L.E. in Interstellar Molecules, ed. B.H. Andrew (Dordrecht: Reidel),
p. 525, 1980.
The Linear Shell Diameter of IRC + 10011. Jewell, P.R., Webber, J.C.,
and Snyder, L.E. Astrophys. J. Lett. 242, L29, 1980.
Radio Detection of Formaldehyde Emission from Comet Halley. Snyder, L.
E., Palmer, P., and de Pater, I. Astron. J. 97, 246-253, 1989.