2008/01/31 by S. P. O’Sullivan, Shane P. O'Sullivan, O'Sullivan, Shane P. +3
Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #Ionosphere and magnetosphere dynamics #Magnetic confinement fusion research #Solar and Space Plasma Dynamics #astro-ph
paper · pdf · doi:10.48550/arxiv.0801.4897
4 pages, 1 figure for the proceedings of 'Approaching Micro-Arcsecond Resolution with VSOP-2: Astrophysics and Technology' (3-7 December 2007, ISAS/JAXA, Sagamihara, Japan)
arxiv created 2008/01/31 · openalex publication_date 2008/01/31 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We are using "broadband" (4.6 to 43 GHz) multi-frequency VLBA polarization observations of compact AGN to investigate the 3-D structure of their jet magnetic (B) fields. Observing at several frequencies, separated by short and long intervals, enables reliable determination of the distribution of Faraday Rotation, and thereby the intrinsic B field structure. Transverse Rotation Measure (RM) gradients were detected in the jets of 0954+658 and 1418+546, providing evidence for the presence of a helical B field surrounding the jet. The RM in the core regions of 2200+420 (BL Lac), 0954+658 and 1418+546 display different signs in different frequency-intervals (on different spatial scales); we suggest an explanation for this in terms of modest bends in a helical B field surrounding their jets. In future, polarization observations with a combination of VSOP-2 at 8, 22 and 43 GHz and ground arrays at frequencies with corresponding resolution will help map out the distributions of Faraday rotation, spectral index and the 3-D B field structure both across the jet and closer to the central engine, providing strong constraints for any jet B field models.