Next Article in Journal
Quantum-Gravitational Effects on Primordial Power Spectra in Slow-Roll Inflationary Models
Next Article in Special Issue
Determining the Jet Poloidal B Field and Black-Hole Rotation Directions in AGNs
Previous Article in Journal / Special Issue
Optical/Infrared Polarised Emission in X-ray Binaries
Article Menu
Issue 1 (March) cover image

Export Article

Open AccessFeature PaperArticle
Galaxies 2018, 6(1), 5; doi:10.3390/galaxies6010005

The Variable Rotation Measure Distribution in 3C 273 on Parsec Scales

Physics Department, Brandeis University, Waltham, MA 02453, USA
Received: 15 September 2017 / Revised: 17 December 2017 / Accepted: 18 December 2017 / Published: 5 January 2018
(This article belongs to the Special Issue Polarised Emission from Astrophysical Jets)
View Full-Text   |   Download PDF [1976 KB, uploaded 5 January 2018]   |  


We briefly review how opacity affects the observed polarization in synchrotron emitting jets. We show some new multi-frequency observations of 3C 273 made with the VLBA in 1999–2000, which add significantly to the available rotation measure (RM) observations of this source. Our findings can be summarized as follows: (1) The transverse gradient in RM is amply confirmed. This implies a toroidal component to the magnetic field, which in turn requires a current of 1017–1018 A flowing down the jet. (2) The net magnetic field in the jet is longitudinal; however, whether or not the longitudinal component is vector-ordered is an open question. (3) The RM distribution is variable on timescales of months to years. We attribute this to the motion of superluminal components behind a turbulent Faraday screen that surrounds the jet. (4) Finally, we suggest that Faraday rotation measurements at higher resolution and higher frequencies, with the Event Horizon Telescope, may enable useful constraints to be placed on the accretion rate onto the central black hole. View Full-Text
Keywords: active galactic nuclei; 3C 273; polarization; opacity; Faraday rotation; magnetic fields active galactic nuclei; 3C 273; polarization; opacity; Faraday rotation; magnetic fields

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Wardle, J. The Variable Rotation Measure Distribution in 3C 273 on Parsec Scales. Galaxies 2018, 6, 5.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Galaxies EISSN 2075-4434 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top