NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-06-26 T07:16:39 PDT
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For refcode 1992ApJ...391..589W:
Retrieve 72 NED objects in this reference.
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Copyright by American Astronomical Society. Reproduced by permission
1992ApJ...391..589W THE MILLIARCSECOND STRUCTURE OF HIGHLY VARIABLE RADIO SOURCES ANN E. WEHRLE, MARSHALL H. COHEN, AND STEPHEN C. UNWIN Owens Valley Radio Observatory, Mail Code 10124, California Institute of Technology, Pasadena, CA 91125 HUGH D. ALLER AND MARGO F. ALLER Radio Astronomy Observatory, University of Michigan, Ann Arbor, MI 48109 AND GEORGE NICOLSON Hartebeesthoek Radio Astronomy Observatory, P.O. Box 443, Krugersdorp 1740, South Africa Received 1990 December 12; accepted 1991 November 20 ABSTRACT We define a new sample of core-dominated extragalactic sources: those whose flux density has exceeded 4.5 Jy at 8 GHz at any epoch. This Variable Source Sample has 41 members. We have begun a program of VLBI studies of those members of the Variable Source Sample which are not otherwise being observed. In this paper we show first-epoch maps 12 of the 13 new objects. We discuss the morphologies and "scale lengths" (analogous to e-folding lengths) of sources in the complete Variable Source Sample to the extent these quantities are known, and compare them to the sources in the complete flux-limited sample of Pearson & Readhead (1988). We also discuss the ratio of X-ray to radio luminosities of sources in the Variable Source Sample. Our principal results are the following: 1. The morphologies of the Variable Source Sample and Pearson-Readhead sources are similar. 2. We confirm the Pearson-Readhead result that the distribution of position angle differences between milliarcsecond and arcsecond scales shows peaks at 0^deg^ and 90^deg^. 3. In our VLBI images, the "scale lengths" of Variable Source Sample and Pearson-Readhead sources are all smaller than about 120 pc. Compact Steep Spectrum sources have the largest scale length; BL Lac objects have much smaller scale lengths. 4. BL Lac objects have significantly higher ratios of X-ray to radio luminosities than the quasars in the Variable Source Sample. Subject headings: galaxies: active - galaxies: jets - galaxies: nuclei - quasars: general - radio continuum: galaxies
Retrieve 72 NED objects in this reference.
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