The Submillimeter Wave Astronomy Satellite
V. Tolls, A. Dalgarno,
N. R. Erickson, G. G. Fazio, P. F. Goldsmith,
M. Harwit, D. J. Hollenbach, D. G. Koch,
G. J. Melnick, D. A. Neufeld,
R. Schieder, R. L. Snell, J. R. Stauffer,
P. Thaddeus, G. F. Winnewisser
SPIE Proceedings of "Infrared Spaceborne Remote Sensing II", Vol. 2268, 1994
Abstract:
The Submillimeter Wave Astronomy Satellite (SWAS) mission will study
galactic star formation and interstellar chemistry. To carry out
this mission, SWAS will survey dense
(n(H2) > 103 cm) molecular clouds
within our galaxy in either the ground-state or a low-lying transition
of five astrophysically important species:
H2O, H218O, O2, CI, and 13CO.
By observing these lines SWAS will: (1) test long-standing theories that
predict that these species are the dominant coolants of molecular clouds
during the early stages of their collapse to form stars and planets
and (2) supply heretofore missing information about the abundance
of key species central to the chemical models of dense interstellar gas.
During its three-year mission, SWAS will observe
giant and dark cloud cores with the goal of detecting
or setting an upper limit on the water abundance of 3*10-6
(relative to H2) and on the molecular oxygen abundance of
2*10-6 (relative to H2).
SWAS is designed to carry all elements of a ground based radiotelescope.
The telescope is a highly efficient 54 x 68 cm off-axis Cassegrain
antenna with an aggregate surface error of less than 11µm rms. The receiver
system consists of two independent heterodyne receivers with second harmonic Schottky
diode mixers, passively cooled to about 150 K. The spectrometer is a single
acousto-optical spectrometer (AOS) with 1400 1-MHz channels enabling to
simultaneously observe the H2O, O2, CI, and 13CO lines.