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Very Long Baseline Interferometry of Galactic OH Sources
Author(s) -
Ronnang B. O.,
Rydbeck O. E. H.,
Moran J. M.
Publication year - 1970
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1029/rs005i010p01227
Subject(s) - very long baseline interferometry , interferometry , physics , radio telescope , haystack , telescope , astrophysics , observatory , angular resolution (graph drawing) , microwave , angular diameter , optics , cosmic microwave background , radio astronomy , astronomy , baseline (sea) , geology , stars , mathematics , combinatorics , quantum mechanics , anisotropy , world wide web , computer science , oceanography
Several hydroxyl radical (OH) microwave emission sources were studied in July 1969 with very long baseline interferometry (VLBI). The elements of the interferometer were the 84‐foot telescope of the Onsala Space Observatory at Chalmers University of Technology, Sweden, and the 120‐foot telescope of the Haystack Microwave Research Facility at Lincoln Laboratory, MIT; a baseline of 31.1×10 6 wavelengths, or a fringe spacing of 0.0066 sec of arc at a frequency of 1665 MHz, resulted. Earlier spectral line interferometric observations have given detailed information on the angular sizes and spatial separations of the 1665‐MHz OH sources in the W3 source. The measurements reported here confirm these results and give additional information on the complex structure of the various features. Four other galactic OH emission sources with unknown angular sizes were also investigated. Only one (the 5‐km/sec component in the 1667‐MHz spectrum of W49) gave reliable fringes.