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Gama Andre B. Perondi Daniel Dewdney Megan M. Fraisse Clyde W. Small Ian M. Peres Natalia A. 《Theoretical and Applied Climatology》2022,149(1-2):83-99
Theoretical and Applied Climatology - Disease alert systems (DAS) of the AgroClimate platform are intended to facilitate grower decision-making when planning fungicide applications. These DAS... 相似文献
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A. Pedlar B. Fernandez N. G. Hamilton M. P. Redman & P. E. Dewdney 《Monthly notices of the Royal Astronomical Society》1998,300(4):1071-1076
We present subarcsecond MERLIN 0.4-GHz (73 cm) and 1.6-GHz (18 cm) radio measurements of the nuclear region of the Seyfert galaxy NGC 4151. By comparison with higher frequency observations, we deduce that one component (C4) shows a low-frequency turnover which we interpret as evidence for free–free absorption by ionized gas with an emission measure between 3 × 105 and 106 pc cm−6 . The free–free absorption appears to be localized to a region ∼50 pc in extent, and we consider models in which the ionized gas may be closely associated with a neutral molecular torus. 相似文献
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J. V. Buckle R. E. Hills H. Smith W. R. F. Dent G. Bell E. I. Curtis R. Dace H. Gibson S. F. Graves J. Leech † J. S. Richer R. Williamson ‡ S. Withington G. Yassin † R. Bennett P. Hastings I. Laidlaw J. F. Lightfoot T. Burgess P. E. Dewdney G. Hovey A. G. Willis R. Redman B. Wooff D. S. Berry B. Cavanagh G. R. Davis J. Dempsey P. Friberg T. Jenness R. Kackley N. P. Rees § R. Tilanus C. Walther W. Zwart T. M. Klapwijk M. Kroug T. Zijlstra 《Monthly notices of the Royal Astronomical Society》2009,399(2):1026-1043
This paper describes a new Heterodyne Array Receiver Program (HARP) and Auto-Correlation Spectral Imaging System (ACSIS) that have recently been installed and commissioned on the James Clerk Maxwell Telescope. The 16-element focal-plane array receiver, operating in the submillimetre from 325 to 375 GHz, offers high (three-dimensional) mapping speeds, along with significant improvements over single-detector counterparts in calibration and image quality. Receiver temperatures are ∼120 K across the whole band, and system temperatures of ∼300 K are reached routinely under good weather conditions. The system includes a single-sideband (SSB) filter so these are SSB values. Used in conjunction with ACSIS, the system can produce large-scale maps rapidly, in one or more frequency settings, at high spatial and spectral resolution. Fully sampled maps of size can be observed in under 1 h.
The scientific need for array receivers arises from the requirement for programmes to study samples of objects of statistically significant size, in large-scale unbiased surveys of galactic and extra-galactic regions. Along with morphological information, the new spectral imaging system can be used to study the physical and chemical properties of regions of interest. Its three-dimensional imaging capabilities are critical for research into turbulence and dynamics. In addition, HARP/ACSIS will provide highly complementary science programmes to wide-field continuum studies and produce the essential preparatory work for submillimetre interferometers such as the Submillimeter Array (SMA) and Atacama Large Millimeter/Submillimeter Array (ALMA). 相似文献
The scientific need for array receivers arises from the requirement for programmes to study samples of objects of statistically significant size, in large-scale unbiased surveys of galactic and extra-galactic regions. Along with morphological information, the new spectral imaging system can be used to study the physical and chemical properties of regions of interest. Its three-dimensional imaging capabilities are critical for research into turbulence and dynamics. In addition, HARP/ACSIS will provide highly complementary science programmes to wide-field continuum studies and produce the essential preparatory work for submillimetre interferometers such as the Submillimeter Array (SMA) and Atacama Large Millimeter/Submillimeter Array (ALMA). 相似文献
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