Titre du document

VRO 42 22 01: a Variable Source with Circular Polarization

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Nom du Corpus

AstroConcepts

Auteur(s)
  • F. BIRAUD 1
  • P. VERON 1
Affiliation(s)
  • Observatoire de Paris, Meudon.
Résumé

THE radio source VRO 42 22 01 was recently identified with a variable stellar object, BL Lac (ref. 1), and we have obtained results which show that the source is radio variable and probably circularly polarized. Since September 1967, a 2,695 MHz receiver has been in operation at the Nancay radiotelescope. It allows simultaneous measurements of flux densities with electric vectors at position angles 0 (V) and 90 (H), and of the products, in phase and through a quarter-wavelength delay, of the two corresponding voltages. It is thus possible to determine the complete polarization, linear or circular, of the most intense sources. One of the programmes in progress with this receiver is the measurement of flux variations for known variable sources, and of possible polarization variations. The radio source VRO 42 22 01 was included in that programme. This source has a flux density at 610.5 MHz of S610 = 4.0 flux units (ref. 2) (1 flux umt = 1026 W/m2 Hz1), but it does not appear in the 4C catalogue3, so S178<2.0 flux units. Its flux density was measured at 1,417 MHz by Williams, and Stewart4, who give S1417 = 7.3 flux units. Its radio spectrum resembles that of the variable components of well known radio sources.

Langue(s) du document
Indéterminé
Année de publication
1968
Revue

Nature

Éditeur
Nature
Type de publication
journal
Type de document
other
Présence de XML structuré
Oui
Version de PDF
1.4
Score de qualité du texte
4.505
Nom du concept
  • Beta Lacertae object
Catégories Science-Metrix
  • 1 - general ; 2 - general science & technology ; 3 - general science & technology
Catégories Inist
  • 1 - sciences appliquees, technologies et medecines ; 2 - sciences biologiques et medicales ; 3 - sciences biologiques fondamentales et appliquees. psychologie
Catégories Scopus
  • 1 - General ; 2 - Multidisciplinary ; 3 - Multidisciplinary
Catégories WoS
  • 1 - science ; 2 - multidisciplinary sciences
Identifiant ISTEX
52988CD34DD1A860AFA7684BC64C7272B6655C72
ark:/67375/GT4-GP3P6SGN-L
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