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IMAGES OF THE BL LA...
IMAGES OF THE BL LACERTAE OBJECT 1749+701 AT 5 GHZ
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- Bååth, L.B. 1948- (författare)
- Onsala Space Observatory, Onsala, Sweden
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- Zhang, F. J. (författare)
- Shanghai Observatory, China
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(creator_code:org_t)
- Les Ulis, France : EDP Sciences, 1992
- 1992
- Engelska.
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Ingår i: Astronomy and Astrophysics. - Les Ulis, France : EDP Sciences. - 0004-6361 .- 1432-0746. ; 262:1, s. 1-7
- Relaterad länk:
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https://urn.kb.se/re...
Abstract
Ämnesord
Stäng
- This paper presents images of 1749+701 from data obtained between 1980 and 1983 as a part of our VLBI programme to monitor a subsample of BL Lac objects at 5GHz. Our images show that this source has a complex structure with a jet pointing towards the north-west at a position angle of about -65-degrees. The brightest component is growing in extension along this position angle. We suggest this to be the core and that the growing extension was caused by a shock generated during an outburst and moving out along the jet. From the extension rate, we obtain an angular separation speed of 0.18 mas yr-1, which corresponds to an apparent transverse speed of 5c. The distances and position angles of two outer components seem remarkably constant. The phenomenon can be understood through a model in which a relativistic jet bends such that its axis is very close to the line of sight in two points. We also deduce that the Lorentz factor must be 4.5 less-than-or-equal-to gamma less-than-or-equal-to 6.5 and that the viewing angle must be 5-degrees less-than-or-equal-to theta less-than-or-equal-to 10-degrees. In this paper, we also present two images obtained from 5GHz MERLIN and combined MERLIN-VLBI data respectively. These maps show that there is a weak component located at a distance of 0.42 arcsec from the core at p.a -155-degrees.
Ämnesord
- NATURVETENSKAP -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)
- NATURAL SCIENCES -- Physical Sciences -- Astronomy, Astrophysics and Cosmology (hsv//eng)
Nyckelord
- BL LACERTAE OBJECTS
- QUASARS
- JETS
- RADIO CONTINUUM
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
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