117 research outputs found

    Far Infrared Spectroscopy

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    Contains a report on a research project

    Analysis of aircraft microwave measurements of the ocean surface

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    A data system was developed to process, from calibrated brightness temperature to computation of estimated parameters, the microwave measurements obtained by the NASA CV-990 aircraft during the 1972 Meteorological Expedition. A primary objective of the study was the implementation of an integrated software system at the computing facility of NASA/GSFC, and its application to the 1972 data. A single test case involving measurements away from and over a heavy rain cell was chosen to examine the effect of clouds upon the ability to infer ocean surface parameters. The results indicate substantial agreement with those of the theoretical study; namely, that the values obtained for the surface properties are consistent with available ground-truth information, and are reproducible except within the heaviest portions of the rain cell, at which nonlinear (or saturation) effects become apparent. Finally, it is seen that uncorrected instrumental effects introduce systematic errors which may limit the accuracy of the method

    Giant Molecular Clouds are More Concentrated to Spiral Arms than Smaller Clouds

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    From our catalog of Milky Way molecular clouds, created using a temperature thresholding algorithm on the Bell Laboratories 13CO Survey, we have extracted two subsets:(1) Giant Molecular Clouds (GMCs), clouds that are definitely larger than 10^5 solar masses, even if they are at their `near distance', and (2) clouds that are definitely smaller than 10^5 solar masses, even if they are at their `far distance'. The positions and velocities of these clouds are compared to the loci of spiral arms in (l, v) space. The velocity separation of each cloud from the nearest spiral arm is introduced as a `concentration statistic'. Almost all of the GMCs are found near spiral arms. The density of smaller clouds is enhanced near spiral arms, but some clouds (~10%) are unassociated with any spiral arm. The median velocity separation between a GMC and the nearest spiral arm is 3.4+-0.6 km/s, whereas the median separation between smaller clouds and the nearest spiral arm is 5.5+-0.2 km/s.Comment: 11 pages, 3 figure

    Radio Astronomy

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    Contains research objectives and reports on three research projects.Joint Services Electronics Programs (U. S. Army, U.S. Navy, and U.S. Air Force) under Contract DA 28-043-AMC-02536(E)U. S. Navy (Office of Naval Research) under Contract N00014-67-A-0204-0009National Science Foundation (Grant GP-7046)National Aeronautics and Space Administration (Contract NSR-22-009-120)National Aeronautics and Space Administration (Grant NsG-419

    Optical and Infrared Spectroscopy

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    Contains research objectives and reports on one research project

    Radio Astronomy

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    Contains reports on three research projects.National Aeronautics and Space Administration (Grant NsG-419)National Aeronautics and Space Administration (Contract NSR-22-009-120)Lincoln Laboratory Purchase Order No. 74

    Radio Astronomy

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    Contains reports on three research projects, with one broken into two subsections.National Aeronautics and Space Administration (Grant NsG-419)National Aeronautics and Space Administration (Contract NSR-22-009-120)Joint Services Electronics Programs (U.S. Army, U.S. Navy, and U.S. Air Force) under Contract DA 28-043-AMC-02536(E

    Full-Polarization Observations of OH Masers in Massive Star-Forming Regions: I. Data

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    We present full-polarization VLBA maps of the ground-state, main-line, 2 Pi 3/2, J = 3/2 OH masers in 18 Galactic massive star-forming regions. This is the first large polarization survey of interstellar hydroxyl masers at VLBI resolution. A total of 184 Zeeman pairs are identified, and the corresponding magnetic field strengths are indicated. We also present spectra of the NH3 emission or absorption in these star-forming regions. Analysis of these data will be presented in a companion paper.Comment: 111 pages, including 42 figures and 21 tables, to appear in ApJ

    Radio Astronomy

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    Contains reports on five research projects.National Aeronautics and Space Administration (Grant NsG-419)National Aeronautics and Space Administration (Contract NSR-22-009-120)Lincoln Laboratory Purchase Order No. 74
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