Stratification in polarization and Faraday rotation in the jet of 3C 120
| Autor: | Gómez Fernández, J. L., Agudo, Iván, Marscher, Alan P., Jorstad, Svetlana G., Roca-Sogorb, Mar |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
active [Galaxies]
Galaxies: jets Polarization Astrophysics::High Energy Astrophysical Phenomena Astrophysics (astro-ph) FOS: Physical sciences jets [Galaxies] galaxies [Radio continuum] Galaxies: active individual (3C 120) [Galaxies] Galaxies: individual (3C 120) Astrophysics Radio continuum: galaxies |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| ISSN: | 2004-0806 |
| DOI: | 10.48550/arxiv.0807.2566 |
| Popis: | 5 pages, 3 figures. Very long baseline interferometric observations of the radio galaxy 3C 120 show a systematic presence of gradients in Faraday rotation and degree of polarization across and along the jet. These are revealed by the passage of multiple superluminal components throughout the jet as they move out from the core in a sequence of 12 monthly polarimetric observations taken with the VLBA at 15, 22, and 43 GHz. The degree of polarization has an asymmetric profile in which the northern side of the jet is more highly polarized. The Faraday rotation measure is also stratified across the jet width, with larger values for the southern side. Superposed on this structure we find a localized region of high Faraday rotation measure ( 6000 rad m2) between approximately 3 and 4 mas from the core. This region of enhanced Faraday rotation may result from the interaction of the jet with the ambient medium, which may also explain the stratification in degree of polarization. The data are also consistent with a helical magnetic field in a two-fluid jet model, consisting of an inner emitting jet and a sheath of nonrelativistic electrons. This research has been supported by the Spanish Ministerio de Educación y Ciencia and the European Fund for Regional Development through grants AYA2004-08067-C03- 03 and AYA2007-67627-C03-03, and by National Science Foundation grant AST-0406865. I. A. acknowledges support by an I3P contract by the Spanish Consejo Superior de Investigaciones Científicas. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|