[ { "id": "authors:sp90j-zf002", "collection": "authors", "collection_id": "sp90j-zf002", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150204-145701950", "type": "article", "title": "High-Resolution Microwave Images of Saturn", "author": [ { "family_name": "Grossman", "given_name": "A. W.", "clpid": "Grossman-A-W" }, { "family_name": "Muhleman", "given_name": "D. O.", "clpid": "Muhleman-D-O" }, { "family_name": "Berge", "given_name": "G. L.", "clpid": "Berge-G-L" } ], "abstract": "An analysis of high-resolution microwave images of Saturn and Saturn's individual rings is presented. Radio interferometric observations of Saturn taken at the Very Large Array in New Mexico at wavelengths of 2 and 6 centimeters reveal interesting new features in both the atmosphere and rings. The resulting maps show an increase in brightness temperature of about 3 K from equator to pole at both wavelengths, while the 6-centimeter map shows a bright band at northern mid-latitudes. The data are consistent with a radiative transfer model of the atmosphere that constrains the well-mixed, fully saturated, NH_3 mixing ratio to be 1.2 x 10^-4 in a region just below the NH_3 clouds, while the observed bright band indicates a 25 percent relative decrease of NH_3 in northern mid-latitudes. Brightness temperatures for the classical rings are presented. Ring brightness shows a variation with azimuth and is linearly polarized at an average value of about 5 percent. The variations in ring polarization suggest that at least 20 percent of the ring brightness is the result of a single scattering process.", "doi": "10.1126/science.245.4923.1211", "issn": "0036-8075", "publisher": "American Association for the Advancement of Science", "publication": "Science", "publication_date": "1989-09-15", "series_number": "4923", "volume": "245", "issue": "4923", "pages": "1211-1215" }, { "id": "authors:actw2-egd07", "collection": "authors", "collection_id": "actw2-egd07", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180720-160139612", "type": "article", "title": "Aperture synthesis observations of Saturn and its rings at 2.7-mm wavelength", "author": [ { "family_name": "Dowling", "given_name": "T. E.", "clpid": "Dowling-T-E" }, { "family_name": "Muhleman", "given_name": "D. O.", "clpid": "Muhleman-D-O" }, { "family_name": "Berge", "given_name": "G. L.", "clpid": "Berge-G-L" } ], "abstract": "We present 2.7-mm interferometric observations of Saturn made near opposition in June 1984 and June 1985, when the ring opening angle was 19\u00b0 and 23\u00b0, respectively. By combining the data sets we produce brightness maps of Saturn and its rings with a resolution of 6\u2033. The maps show flux from the ring ansae, and are the first direct evidence of ring flux in the 3-mm wavelength region. Modelfits to the visibility data yield a disk brightness temperature of 156 \u00b1 5\u00b0K, a combined A, B, and C ring brightness temperature of 19 \u00b1 3\u00b0K, and a combined a ring cusp (region of the rings which block the planet's disk) brightness temperature of 85 \u00b1 5\u00b0K. These results imply a normal-to-the-ring optical depth for the combined A-B-C ring of 0.31 \u00b1 0.04, which is nearly the same value found for wavelenghts from the UV to 6 cm. About 6\u00b0K of the ring flux is attributed to scattered planetary emission, leaving an intrinsic thermal component of \u223c13\u00b0K. These results, together with the ring particle size distributions found by the Voyager radio occultation experiments, are consistent with the idea that the ring particles are composed chiefly of water ice.", "doi": "10.1016/0019-1035(87)90092-3", "issn": "0019-1035", "publisher": "Elsevier", "publication": "Icarus", "publication_date": "1987-06", "series_number": "3", "volume": "70", "issue": "3", "pages": "505-516" }, { "id": "authors:ez5w2-27m46", "collection": "authors", "collection_id": "ez5w2-27m46", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181211-080024412", "type": "book_section", "title": "Reference Frame Studies at JPL/Caltech", "book_title": "XIXth General Assembly of the IAU", "author": [ { "family_name": "Dickey", "given_name": "J. O.", "clpid": "Dickey-J-O" }, { "family_name": "Esposito", "given_name": "P. B.", "clpid": "Esposito-P-B" }, { "family_name": "Lestrade", "given_name": "J.-F.", "clpid": "Lestrade-J-F" }, { "family_name": "Linfield", "given_name": "R. P.", "clpid": "Linfield-R-P" }, { "family_name": "Melbourne", "given_name": "W. G.", "clpid": "Melbourne-W-G" }, { "family_name": "Newhall", "given_name": "X. X.", "clpid": "Newhall-X-X" }, { "family_name": "Niell", "given_name": "A. E.", "clpid": "Niell-A-E" }, { "family_name": "Preston", "given_name": "R. A.", "clpid": "Preston-R-A" }, { "family_name": "Standish", "given_name": "E. M.", "clpid": "Standish-E-M" }, { "family_name": "Williams", "given_name": "J. G.", "clpid": "Williams-J-G" }, { "family_name": "Muhleman", "given_name": "D. O.", "clpid": "Muhleman-D-O" }, { "family_name": "Berge", "given_name": "G. L.", "clpid": "Berge-G-L" }, { "family_name": "Rudy", "given_name": "D. J.", "clpid": "Rudy-D-J" } ], "contributor": [ { "family_name": "Swings", "given_name": "Jean-Pierre", "clpid": "Swings-J-P" } ], "abstract": "In recent years, a revolution in astronomical position measurements has been taking place with the advent of modern space techniques. These new techniques, which supplement the traditional astrometric measurements, include laser ranging to the moon and artificial satellites, very-long-baseline interferometry (VLBI) of galactic and extra-galactic radio sources and spacecraft, radio tracking of satellites, and radar-ranging and spacecraft tracking during planetary encounters. Impressive accuracies have been achieved and further improvements are forthcoming. Each technique can be expected to establish its own reference frame which is derived from observations of a particular class of objects. The celestial and terrestrial coordinate systems are related through adopted constants and definitions. Contemporary astronomy has led to the development of three principal celestial coordinate systems: the optical frame (FK4/FK5) based on positions of galactic stars; the planetary/lunar ephemeris frame based on the major celestial bodies of the solar system; and the radio frame constructed from observations of extragalactic radio sources (quasars). Each frame is rotated with respect to others; furthermore, the optical frame offset is time variable. It is important that all frames be interconnected and unified. The optical frame is being connected to the radio frame by VLBI observations of radio emitting stars. The radio frame is being tied to the ephemeris frame in several ways \u2013 one is via differential VLBI measurements between quasars and planet-orbiting spacecraft.", "doi": "10.1017/S1539299600006274", "isbn": "9789027722782", "publisher": "D. Reidel", "place_of_publication": "Dordrecht", "publication_date": "1986", "pages": "93-96" }, { "id": "authors:fp50j-zba02", "collection": "authors", "collection_id": "fp50j-zba02", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150130-121531674", "type": "article", "title": "Uranus: microwave images", "author": [ { "family_name": "Jaffe", "given_name": "Walter J.", "clpid": "Jaffe-W-J" }, { "family_name": "Berge", "given_name": "Glenn L.", "clpid": "Berge-G-L" }, { "family_name": "Owen", "given_name": "Tobias", "clpid": "Owen-T" }, { "family_name": "Caldwell", "given_name": "John", "clpid": "Caldwell-J" } ], "abstract": "Observations of Uranus at wavelengths of 2 and 6 centimeters with the Very Large Array were made in 1980 and 1981. The resulting maps of brightness temperature show a subsolar symmetry at 2 centimeters but a near-polar symmetry at 6 centimeters. The 6-centimeter maps show an increase in temperature from equator to pole with some evidence for a warm \"ring\" surrounding the north pole. The disk-average temperatures (147 +/- 5 K and 230 +/- 6 K at 2 and 6 centimeters, respectively) are distinctly lower than recently reported values; these results suggest that the secular increase in temperature reported during the last 15 years has been reversed. The variations in brightness temperature probably reflect variations in ammonia abundance in the planet's atmosphere, but the mechanism driving these variations is still unclear.", "doi": "10.1126/science.11541997", "issn": "0036-8075", "publisher": "American Association for the Advancement of Science", "publication": "Science", "publication_date": "1984-02-23", "series_number": "4662", "volume": "225", "issue": "4662", "pages": "619-621" }, { "id": "authors:thg5p-fc183", "collection": "authors", "collection_id": "thg5p-fc183", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150205-151514779", "type": "article", "title": "Microwave Measurements of Carbon Monoxide on Titan", "author": [ { "family_name": "Muhleman", "given_name": "D. O.", "clpid": "Muhleman-D-O" }, { "family_name": "Berge", "given_name": "G. L.", "clpid": "Berge-G-L" }, { "family_name": "Clancy", "given_name": "R. T.", "clpid": "Clancy-R-T" } ], "abstract": "The ratio of the flux density of Titan was measured in two 200-megahertz bands, one centered on the (1-0) rotation line of carbon monoxide at 115.3 gigahertz and the other 2600 megahertz lower. The measurements were made with a complex-correlation technique on the new millimeter-wavelength interferometer at the Owens Valley Radio Observatory, Big Pine, California. The excess flux in the carbon monoxide band is interpreted as a strong detection of carbon monoxide and a mixing ratio, assumed constant, of 6 x 10^(-5). The brightness temperature of Titan at 112.6 gigahertz is 69 \u00b1 10 kelvins, consistent with atmospheric emission from just below the tropopause.", "doi": "10.1126/science.223.4634.393", "issn": "0036-8075", "publisher": "American Association for the Advancement of Science", "publication": "Science", "publication_date": "1984-01-27", "series_number": "4634", "volume": "223", "issue": "4634", "pages": "393-396" }, { "id": "authors:gnwqg-fd822", "collection": "authors", "collection_id": "gnwqg-fd822", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160421-164244322", "type": "book_section", "title": "Aperture Synthesis Maps of CO Emission from M51", "author": [ { "family_name": "Lo", "given_name": "K. Y.", "clpid": "Lo-K-Y" }, { "family_name": "Berge", "given_name": "G.", "clpid": "Berge-G-L" }, { "family_name": "Claussen", "given_name": "M.", "clpid": "Claussen-M-J" }, { "family_name": "Heiligman", "given_name": "G.", "clpid": "Heiligman-G-M" }, { "family_name": "Keene", "given_name": "J.", "clpid": "Keene-Jocelyn" }, { "family_name": "Masson", "given_name": "C.", "clpid": "Masson-C" }, { "family_name": "Phillips", "given_name": "T.", "clpid": "Phillips-T-G" }, { "family_name": "Sargent", "given_name": "A.", "orcid": "0000-0002-4633-5098", "clpid": "Sargent-A-I" }, { "family_name": "Scoville", "given_name": "N.", "orcid": "0000-0002-0438-3323", "clpid": "Scoville-N-Z" }, { "family_name": "Watson", "given_name": "D.", "clpid": "Watson-D" }, { "family_name": "Woody", "given_name": "D.", "clpid": "Woody-D-P" }, { "literal": "International Union of Radio Science" }, { "literal": "Instituto de Radioastronomia Milimetrica" } ], "abstract": "7\"-resolution maps of CO emission from the central 2' of M51 have been made with the Owens Valley millimeter-wave interferometer. Relative warm gas from giant molecular clouds is seen largely confined to arms coincident with the dust lanes, forming coherent structure on the scale of ~3 Kpc. There is a minimum of CO emission within 400 pc of the center. Integrated CO intensity maps are presented. Non-circular motion of the CO gas is evident from the velocity field.", "publisher": "International Union of Radio Science", "publication_date": "1984" }, { "id": "authors:vnsfy-t1r07", "collection": "authors", "collection_id": "vnsfy-t1r07", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160421-082902012", "type": "book_section", "title": "The Caltech Millimeter Wave Interferometer", "author": [ { "family_name": "Masson", "given_name": "C. R.", "clpid": "Masson-C-R" }, { "family_name": "Berge", "given_name": "G. L.", "clpid": "Berge-G-L" }, { "family_name": "Claussen", "given_name": "Mark J.", "clpid": "Claussen-M-J" }, { "family_name": "Heiligman", "given_name": "G. M.", "clpid": "Heiligman-G-M" }, { "family_name": "Leighton", "given_name": "R. B.", "clpid": "Leighton-R-B" }, { "family_name": "Lo", "given_name": "K. Y.", "clpid": "Lo-K-Y" }, { "family_name": "Moffett", "given_name": "A. T.", "clpid": "Moffett-A-T" }, { "family_name": "Phillips", "given_name": "T. G.", "clpid": "Phillips-T-G" }, { "family_name": "Sargent", "given_name": "Anneila I.", "orcid": "0000-0002-4633-5098", "clpid": "Sargent-A-I" }, { "family_name": "Scott", "given_name": "S. L.", "clpid": "Scott-S-L" }, { "family_name": "Woody", "given_name": "David P.", "clpid": "Woody-D-P" }, { "family_name": "Young", "given_name": "A.", "clpid": "Young-A" }, { "literal": "International Union of Radio Science" }, { "literal": "Instituto de Radioastronomia Milimetrica" } ], "abstract": "The Caltech Millimeter-Wave Interferometer has recently begun observations at a wavelength of 2.6 mm. We describe the instrument and some of the first results from it.", "publisher": "International Union of Radio Science", "publication_date": "1984" }, { "id": "authors:q2zba-5k493", "collection": "authors", "collection_id": "q2zba-5k493", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151109-142043082", "type": "article", "title": "Callisto: Disk Temperature at 3.71-Centimeter Wavelength", "author": [ { "family_name": "Berge", "given_name": "Glenn L.", "clpid": "Berge-G-L" }, { "family_name": "Muhleman", "given_name": "Duane O.", "clpid": "Muhleman-D-O" } ], "abstract": "We observed the radio emission of Callisto with a three-element interferometer at the time of the 1973 opposition of Jupiter. Special care was taken to remove the residual, unresolved contribution from Jupiter itself in the antenna side lobes. The resulting disk temperature at a wavelength of 3.71 centimeters, assuming a radius of 2500\u00b175 kilometers for Callisto, was 101\u00b0\u00b125\u00b0K. This temperature is much more consistent with emission from a simple dielectric sphere than the considerably higher temperatures that have been reported for wavelengths of 3.5 and 8.2 millimeters.", "doi": "10.1126/science.187.4175.441", "issn": "0036-8075", "publisher": "American Association for the Advancement of Science", "publication": "Science", "publication_date": "1975-02-07", "series_number": "4175", "volume": "187", "issue": "4175", "pages": "441-443" } ]