| 1. |
- Romney, J., et al.
(författare)
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The milliarcsecond scale structure of low frequency variable sources
- 1984
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Ingår i: Astronomy and Astrophysics. - Les Ulis : EDP Sciences. - 0004-6361 .- 1432-0746. ; 135:2, s. 289-299
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Tidskriftsartikel (refereegranskat)abstract
- VLBI observations were performed of 21 radio sources which exhibit low frequency variability. The integrated flux densities, variability indices at 0.4 GHz, optical magnitudes, redshifts, spectral indices at 0.4 GHz, and flux intensities with respect to a reference energy flux are provided. The VLBI data were synthesized from observatories located on different continents around the world. All structures were emitted from compact sources with sizes confined to milliarcsc scales. Nearly half displayed core-jet morphologies, while 28 percent had complex structures and 14 percent had either simple structures or were not resolvable. Further observations are proceeding at 400 mHz to confirm the presence of synchrotron electrons and magnetic fields ejected at relativistic speeds along the line of sight, which has the appearance of superluminal velocities.
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| 2. |
- Bååth, L.B. 1948-, et al.
(författare)
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High Resolution Observations of the QSO 3C 345 at 1.3 centimeters
- 1981
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Ingår i: Astrophysical Journal. - Philadelphia, PA : Institute of Physics Publishing (IOPP). - 0004-637X .- 1538-4357. ; 243, s. L123-L126
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Tidskriftsartikel (refereegranskat)abstract
- High-resolution VLBI observations made at a frequency of 22.235 GHz of the quasar 3C 345 are discussed. Antennas located at the Crimean Astrophysical Observatory, USSR; Onsala, Sweden; Effelsberg, West Germany; and the Haystack Observatory, Massachusetts were employed at 4-min integration times to provide baselines ranging up to 5.5 x 10 to the 8th wavelengths. About 40% of the total flux density of 7.85 Jy, observed in November 1977, and 8.05 Jy, observed in October 1978, is found to originate in an unresolved component of the quasar core in a region less than 0.1 milliarcsec in diameter. The elongated jet-like component of the quasar is observed to contain several peaks of emission extending up to 6 milliarsec from the core which decreased in extent between the two observations.
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