| Attributs | Valeurs |
|---|
| type
| |
| Is Part Of
| |
| Subject
| |
| Title
| - The HST survey of the B2 sample of radio-galaxies: Optical nuclei and the FR I/BL Lac unified scheme
|
| Date
| |
| has manifestation of work
| |
| related by
| |
| Author
| |
| Abstract
| - We examine the optical properties of the nuclei of low luminosity radio-galaxies using snapshot HST images of the B2 sample. In agreement with the results obtained from the analysis of the brighter 3C/FR I sample, we find a correlation between fluxes (and luminosities) of the optical and radio cores. This provides further support for the interpretation that the optical nuclear emission in FR I is dominated by synchrotron emission and that accretion in these sources takes place in a low efficiency radiative regime. In the framework of the FR I/BL Lacs unified scheme, we find that the luminosity difference between FR I and BL Lac nuclei can be reproduced with a common beaming factor in both the radio and the optical band, independent of the extended radio luminosity, thus supporting such a scenario. The corresponding bulk Lorentz factor is significantly smaller than is expected from observational and theoretical considerations in BL Lacs: this can be interpreted as due to a velocity structure in the jet, with a fast spine surrounded by a slower layer.
|
| article type
| |
| publisher identifier
| |
| Date Copyrighted
| |
| Rights
| |
| Rights Holder
| |
| is part of this journal
| |
| is primary topic
of | |
