Results 131 to 140 of about 569 (189)

Submillimeter astronomy (heterodyne spectroscopy)

Proceedings of the IEEE, 1992
Some of the aspects of submillimeter-wave astronomy which are relevant to the field of heterodyne spectroscopy are reviewed. Most of the discussion concerns the dense interstellar medium where stars are forming, with some work presented on nearby galaxies.
T.G. Phillips, J. Keene
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Submillimeter receivers for radio astronomy

Proceedings of the IEEE, 1992
The state of development of receivers for submillimeter-wave radio astronomy is reviewed. Bolometers for continuum observation, hot-electron mixer receivers for narrowband spectral line observation, and heterodyne receivers, both Schottky diode and superconducting tunnel junction, are presented.
R. Blundell, C.-y.E. Tong
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Low-pass interference filters for submillimeter astronomy

Applied Optics, 1980
Low-pass (long-wave transmitting) interference filters, suitable for broadband photometric observations, previously have been constructed from series of capacitive grids stretched on thin Mylar. These filters have the desired optical properties of high transmission, sharp cut-ons, and good blocking at short wavelengths.
S E, Whitcomb, J, Keene
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The Submillimeter Wave Astronomy Satellite: Mission science objectives

Advances in Space Research, 1995
The Submillimeter Wave Astronomy Satellite (SWAS) mission is dedicated to the study of star formation and interstellar chemistry. To carry out this mission, SWAS will survey dense (nH2 > 103 cm−3) 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
Melnick, GJ, Dalgarno, A, Erickson, NR, Fazio, GG, Goldsmith, PF, Harwit, M, Hollenbach, DJ, Koch, DG, Neufeld, DA, Schieder, R, Snell, RL, Stauffer, JR, Thaddeus, P, Tolls, V, Winnewisser, GF   +14 more
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Submillimeter astronomy and cosmology

Space technology and applications international forum (STAIF - 97), 1997
In this paper I summarize some key astrophysics questions and the future space missions needed to address them. These missions, and the questions that drive them, fall under the aegis of two of the four thematic areas of NASA’s Office of Space Science: “The Astronomical Search for Origins and Planetary Systems” covers astrophysics in the near-infrared,
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Submillimeter Heterodyne Astronomy from Mauna Kea

1981 International Conference on Submillimeter Waves and Their Applications, 1981
This paper reports on the results of a collaboration between NASA Goddard Space Flight Center and MIT Lincoln Laboratory in which a laser heterodyne receiver was developed and used at the NASA infrared telescope on Mauna Kea. The NASA IRTF is located on the island of Hawaii at an elevation of 14000 ft (4200 m).
D. Buhl, G. Chin, H. R. Fetterman, D. D. Peck, B. J. Clifton, P. E. Tannenwald, G. A. Koepf   +6 more
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Submillimeter astronomy and developments in China

2014 XXXIth URSI General Assembly and Scientific Symposium (URSI GASS), 2014
Millimeter to submillimeter radio astronomy is one of the frontier areas in Chinese astronomy. The major research activities include molecular clouds, star formation, formation and evolutions of galaxies. Purple Mountain Observatory (PMO) is the major institute in China responsible for mm/submm astronomy and developments.
Sheng-Cai Shi, Ji Yang
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Millimeter and submillimeter wave astronomy

Annual Meeting Optical Society of America, 1986
The interstellar medium consists of diffuse clouds and dense clouds containing atoms, molecules, and dust particles at temperatures ranging from 3 to several hundred kelvins. The dense cloud gas particles are mostly molecular and the species found vary from simple molecules such as H2, CO, CS, HCN, etc.
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Techniques of Submillimeter Astronomy

1988
This review discusses the relative merits of direct and heterodyne techniques for detection in the submillimeter band. A variety of astronomical observing conditions is examined, including those for mountain-top and space telescopes. The spectral resolution (Δν/ν) of the observation is shown to be an important factor in the decision between direct and ...
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Submillimeter Astronomy Reaches New Heights

Science, 1999
LLANO DE CHAJNANTOR, CHILE-- High in the Chilean Andes, over 5000 meters above sea level, astronomers are planning the world9s loftiest observatory: a 10-kilometer-wide array of dishes to peer into the universe9s cold recesses and open a sharp eye on celestial features ranging from surface markings on Pluto to extrasolar planets to the dusty ...
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