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Träfflista för sökning "LAR1:hh srt2:(1985-1989);srt2:(1987)"

Sökning: LAR1:hh > (1985-1989) > (1987)

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1.
  • Bååth, L.B., 1948- (författare)
  • High Resolution Observations of Low Frequency Variables at 932 MHz
  • 1987
  • Ingår i: The Impact of VLBI on Astrophysics and Geophysics : Proceedings of the 129th Symposium of the International Astronomical Union held in Cambridge, Mass., U.S.A., May 10-15, 1987. - Dordrecht : Kluwer Academic Publishers. - 90-277-2704-X - 90-277-2705-8 ; s. 117-118
  • Bokkapitel (refereegranskat)abstract
    • <p>Fifteen sources known to be varying at low frequencies have been observed at six epochs during 1983–84 with a global VLBI array. Some of the sources show structural variations similar to the superluminals. Beaming effect may therefore play an important role at low as well as at higher frequencies.</p>
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2.
  • Bååth, L.B., 1948- (författare)
  • Superluminal Motion in CTA 102
  • 1987
  • Ingår i: Superluminal Radio Sources : Proceedings of a Workshop in honor of Professor Marshall H. Cohen, held at Big Bear Solar Observatory, California, October 28-30, 1986. - Cambridge : Cambridge University Press. - 0-521-34560-X ; s. 206-210
  • Bokkapitel (refereegranskat)
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3.
  • Matveyenko, L.I., et al. (författare)
  • Studies of the 3c 345 Quasar Structure at Dm-Wavelengths
  • 1987
  • Ingår i: Observational evidence of activity in galaxies : proceedings of the 121st Symposium of the International Astronomical Union, held in Byurakan, Armenia, U.S.S.R., June 3-7, 1986. - Dordrecht : D. Reidel Publishing Group. - 90-277-2473-3 - 90-277-2474-1 ; s. 301-304
  • Konferensbidrag (refereegranskat)abstract
    • <p>The structure of the quasar 3C 345 has been studied at 18 and 49 cm wavelengths by VLBI method. The structure has a nucleus and a jet, which changes direction with distance from the nucleus. The continuum emission of the nucleus and the jet regions correspond to a source with a large optical depth, the cut frequence goes down with increasing distance from nucleus.</p>
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4.
  • Mundy, Lee G., et al. (författare)
  • Sonic linewidths in warm clouds?
  • 1987
  • Ingår i: Molecular clouds in the Milky Way and external galaxies : Proceedings of a Symposium Held at the University of Massachusetts in Amherst, November 2-4, 1987. - Berlin/Heidelberg : Springer Berlin/Heidelberg. - 0-387-50438-9 ; s. 235-237
  • Konferensbidrag (refereegranskat)
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5.
  • Tang, Guoquiang, et al. (författare)
  • Radio source structure from geodetic VLBI observations : 8 GHz multi-epoch maps of the quasar 4C 39.25
  • 1987
  • Ingår i: Astronomy and Astrophysics. - Les Ulis : EDP Sciences. - 0004-6361 .- 1432-0746. ; 185:1-2, s. 87-93
  • Tidskriftsartikel (refereegranskat)abstract
    • <p>Techniques for estimating and/or eliminating the effects of structure variations in the extragalactic radio sources used as fiducial points in 8.3-GHz geodetic VLBI observations are described and demonstrated. Particular attention is given to the data base statistics, the calibration of visibility data, the production of hybrid maps with AIPS, and the implementation of these steps in a software package. A set of X-band maps of 4C 39.25, obtained with the receivers of the Mark III dual-frequency VLBI network at six epochs during 1980-1985, is presented. Such maps are shown to be of value (1) for maintaining submarcsec accuracy in the extragalactic reference frame and (2) for qualitative astronomical monitoring of the sources. In 4C 39.25, for example, apparent superluminal motions, complex internal kinematics, and a double western component are observed.</p>
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6.
  • Weisner, Stefan, 1954- (författare)
  • The relation between wave exposure and distribution of emergent vegetation in a eutrophic lake
  • 1987
  • Ingår i: Freshwater Biology. - Chichester, United Kingdom : Wiley-Blackwell. - 0046-5070 .- 1365-2427. ; 18:3, s. 537-544
  • Tidskriftsartikel (refereegranskat)abstract
    • <p>Maximum water depth penetration and changes in horizontal distribution during 39yr of the emergent vegetation in Lake Krankesjon, S Sweden, were investigated. The capacity of the emergent vegetation to penetrate into deeper water areas was higher at wave exposed than at sheltered sites. Differences in biomass and biomass allocation of the dominant species, Phragmites australis, between an exposed and a sheltered site suggest that horizontal expansion towards deeper water at sheltered sites is limited by unfavourable substrate conditions.</p>
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