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ABSTRACT: The results of VLBI observations of the quasar 3C138 at 1667 MHz are
presented. The source is about 0.45 arcsec long and has one widely
separated component that departs considerably from the overall source
linearity. The structure indicates a core/one-sided-jet morphology and
concurs with the structure found ten years ago at 2631 MHz. Topics
covered include superluminal motions, magnetic field strength, and
polarization. The energy loss rate is given as approximately 10 to the
46th erg/s. No evidence for an extended radio component was found, and
consequently, it is suggested that the observed jet is inefficient in
transferring the energy it carries to large distances and dissipates all
of it by bulk kinetic energy losses, or in the first few kpc before
dying.
Astronomy and Astrophysics 01/1984; 131:232-236. · 4.59 Impact Factor
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ABSTRACT: The results of recent very long baseline interferometry of G127.11+0.54 at 10.65 GHz reveal a core dual 'jet' structure. The morphology and physical properties of the compact source are similar to those of SS 433. The combined data from various studies of this object suggest that G127.11+0.54 may be the stellar remnant of the supernova event which also produced the supernova remnant G127.1+0.5.
10/1982;
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ABSTRACT: Compact radio sources whose positions lie within the outlines of supernova remnants may be the stellar remnants of supernova explosions and, if they are related to the supernova remnants, may be used to explore the nature of any morphological connection between the Galactic and extragalactic radio sources. Three such compact sources, G 127.11+0.54, CL 4, and 2051+433, have been observed at 10.65 GHz with an array of very long baseline interferometers having elements in the USA and West Germany. The radio source 2051+433 was also observed briefly at 5.01 GHz. The measured size of CL 4 at 10.65 GHz is about 0.0005 arcsec and seems to be dominated by the effects of interstellar scattering. No fringes were seen in 2051+433, and results indicate there is no compact component of 2051+433 smaller than 0.001 arcsec radiating at 10.65 GHz above a level of about 50 mJy. The possibility is presented that G 127.11+0.54 is a Galactic object. It is found to consist of two components separated by about 0.002 arcsec and oriented perpendicular to both the radio bridge of the supernova remnant G 127.1+0.5 and the underlying optical image. G 127.11+0.54, if Galactic, lies at the extreme low-luminosity end of an apparent continuum of Galactic and extragalactic compact radio source luminosities.
09/1981;
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ABSTRACT: Observations of SS433 made on June 12, 1979, from West Germany, Massachusetts, and West Virginia are discussed. It is noted that SS433 did not show fringes on any baseline although all the calibration sources were seen at their expected strengths. The measured total flux density of SS433 was found to be approximately 0.5 Jy, consistent with previous observations. The source was observed by on-offs at each telescope, which indicates that they were all pointed properly during the observations. The absence of fringes is not attributed to poor observing conditions or instrumental difficulties. It is concluded that if all the 10.65 GHz radiation emanates from a single component, then that component is at least 0.005 arcsec (approximately 10 to the 14th cm) in size. The measurements made on more sensitive intercontinental baselines indicate that there is no component of SS433 smaller than 0.001 arcsec emitting 10.65 GHz radiation above a level of 50 mJy.
06/1981;
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R. C. Walker,
A. C. S. Readhead,
G. A. Seielstad,
R. A. Preston,
A. E. Niell,
G. M. Resch,
P. C. Crane,
D. B. Shaffer, B. J. Geldzahler,
S. G. Neff,
I. I. Shapiro,
D. L. Jauncey,
G. D. Nicolson
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ABSTRACT: SS 433 was detected and partially resolved at 2290 MHz on baselines with
fringe spacings of 1.4, 0.1, and 0.003 arcsec. It was also detected at
8420 MHz on a baseline with a fringe spacing of 0.009 arcsec. Simple
models of the source, consistent with the limited data, have elongated
structures greater than 0.1 arcsec in size with position angles in 1979
May that were within about 10 deg of the position angle of the apparent
bulges of the supernova remnant W50. The data also imply that the source
contains a core less than 0.002 arcsec in size with a brightness
temperature greater than 10 to the 9th K. The bright core and aligned
structures that seem to be present in SS 433 and W50 resemble the
structures seen in powerful extragalactic radio sources which are many
orders of magnitude larger.
The Astrophysical Journal 12/1980; 243:589-596. · 6.02 Impact Factor
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03/1979;
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Astronomy and Astrophysics 07/1978; 68:L11-L13. · 4.59 Impact Factor
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ABSTRACT: Measurements at 9.5 mm are presented of a complete sample of 56 sources
with flux densities at 5 GHz larger than 1 Jy and with flat spectra.
Most of the sources in the sample show a steepening in the spectra in
the frequency range 5-20 GHz, indicating that few of these sources
contain components which are opaque at short centimeter wavelengths.
The Astronomical Journal 04/1978; 83:475-477. · 4.03 Impact Factor
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ABSTRACT: The brightest compact radio source in the nucleus of M82 has a linear diameter of about 0.02 parsecs (25 light-days). On the basis of this small size and energy considerations, it seems that this source is probably not a supernova remnant, but is similar in nature to the compact radio sources found in the nuclei of spiral and elliptical galaxies, Seyfert galaxies, radio galaxies, and in quasi-stellar objects.
08/1977;
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ABSTRACT: Very-long-baseline interferometer observations show that the compact radio source at the Galactic Center has dimensions of approximately 200 AU and that about 25% of the emission comes from a region only 10 AU across. There is no evidence for any expansion or contraction of this compact source, with a velocity of at least a few tens of kilometers per second.
07/1977;
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Astronomy and Astrophysics, 131, 232 - 236 (1984).
