Associate Professor
Experimental and Observational Infrared Astronomy
(949) 824-6280
Professor Garden earned his B.Sc. (1983) and Ph. D. (1987) degrees from the University of Edinburgh, Scotland. He held a postdoctoral position at the University of California, Berkeley before joining the Physics Department at UCI in 1988. Since his arrival at UCI, Professor Garden has received both an Alfred P. Sloan Fellowship (1989-91) and an NSF Young Investigator (1992-97) award.
Although optical astronomy has played, and will continue to play, a pivotal role in the development of our understanding of the physical and chemical composition of the Universe, observations at optical wavelengths are severely hampered by the absorption and scattering of optical photons by cosmic dust. Fortunately, as a result of their relatively small size, the opacity of cosmic dust grains decreases rapidly with increasing wavelength. Astronomical observations at infrared and longer wavelengths thus provide a powerful probe of the physical and chemical composition of dusty regions of the Universe that are invisible to optical photons, such as starforming regions within the cores of giant molecular clouds and the dusty nuclei of galaxies. Another important application of infrared astronomy is in the study of the thermal emission from "cool" (i.e., 100 - 1000 K) celestial objects, such as proto-stars, proto-planetary disks, and brown dwarfs.
Professor Garden's research encompasses a broad spectrum of both experimental and observational infrared astronomy. On the experimental front, he is the Principle Investigator of a project to design and construct a state-of-the-art mid-infrared (lambda = 5 - 30 mu m) imaging Fabry-Perot interferometer for use on the new Keck Telescopes. When completed, the UCI imaging interferomenter will be the most powerful instrument of its kind in the world. Examples of proposed observing projects include a search for dusty proto-planetary disks around a complete sample of nearby solar-type stars, a survey for proto-stars in the cores of giant molecular clouds and a search for infrared radiation from primeval galaxies in the early universe.
On the observational front, Professor Garden is actively involved in several observational programs to study the dynamical and chemical composition of supersonic winds associated with early star formation. Such winds are prevalent in starforming regions and knowledge of their physical properties is essential for a complete understanding of the star formation process. Additional projects include an observational study of the kinematics of interstellar shocks associated with supernova blast waves and a determination of the mass of the black hole at the center of our galaxy from a study of the orbital dynamics of the surrounding gas and stars.
In addition to his research, Professor Garden enjoys teaching and is actively involved with the design and construction of a new robotic astronomical telescope facility to be built on the UCI campus for undergraduate education.
Representative Publications
Images of Shock-Excited Molecular Hydrogen in Young Stellar Outflows, Garden et al., Astrophys. Jour. 354, 232 (1990).
A Spectroscopic Study of the DR21 Outflow Source II. The H_2 Line Emission, Garden et al., Astrophys. Jour. 366, 474 (1991).
A Spectoscopic Study of the DR21 Outflow Source III. The CO Line Emission, Garden et al., Astrophys. Jour. 374, 540 (1991).
High-Velocity HCO+ Emission Associated with the DR21 Molecular Outflow, Garden et al., Astrophys. Jour. 392, 602 (1992).
Wind/Clump Interactions in Young Stellar Outflows, Garden et al., Astrophys. Jour., in press (1993).