Helical magnetic field structure in 3C 273 A Faraday rotation analysis using multi-frequency polarimetric VLBA data

We present a study on rotation measure (RM) of the quasar 3C 273. This analysis aims to discern the magnetic field structure and its temporal evolution. The quasar 3C 273 is one of the most studied active galactic nuclei due to its high brightness, strong polarisation, and proximity, which enables t...

Descripción completa

Detalles Bibliográficos
Autores: Toscano, Teresa, Molina, Sol, Gómez Fernández, José L., Zeng, Ai-Ling, Dahale, Rohan, Cho, I., Moriyama, K., Wielgus, Maciek, Fuentes, Antonio, Foschi, Marianna, Röder, Jan, Myserlis, Ioannis, Angelakis, Emmanouil, Zensus, Anton
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/393929
Acceso en línea:http://hdl.handle.net/10261/393929
Access Level:acceso abierto
Palabra clave:Methods: observational
Techniques: interferometric
Techniques: polarimetric
Galaxies: jets
Galaxies: magnetic fields
Quasars: general
Descripción
Sumario:We present a study on rotation measure (RM) of the quasar 3C 273. This analysis aims to discern the magnetic field structure and its temporal evolution. The quasar 3C 273 is one of the most studied active galactic nuclei due to its high brightness, strong polarisation, and proximity, which enables the resolving of the transverse structure of its jet in detail. We used polarised data from 2014, collected at six frequencies (5, 8, 15, 22, 43, 86 GHz) with the Very Long Baseline Array, to produce total and linear polarisation-intensity images, as well as RM maps. Our analysis reveals a well-defined transverse RM gradient across the jet, indicating a helical, ordered magnetic field that threads the jet and likely contributes to its collimation. Furthermore, we identified temporal variations in the RM magnitude when compared with prior observations. These temporal variations show that the environment around the jet is dynamic, with changes in the density and magnetic field strength of the sheath that are possibly caused by interactions with the surrounding medium. © The Authors 2025