A model of the polarization position-angle swings in BL Lacertae objects

Konigl,, A and Choudhuri, Arnab Rai (1985) A model of the polarization position-angle swings in BL Lacertae objects. In: Astrophysical Journal, 289 (1). pp. 188-192.

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Abstract

The polarization position-angle swings that have been measured in a number of BL Lacertae objects and highly variable quasars are interpreted in terms of shock waves which illuminate (by enhanced synchrotron radiation) successive transverse cross sections of a magnetized, relativistic jet. The jet is assumed to have a nonaxisymmetric magnetic field configuration of the type discussed in the companion paper on the equilibria of force-free jets. For a jet that is viewed at a small angle to the axis, the passage of a shock will give rise to an apparent rotation of the polarization position angle whose amplitude can be substantially larger than 180 deg. The effects of freely propagating shocks are compared with those of bow shocks which form in front of dense obstacles in the jet, and specific applications to 0727 - 115 and BL Lacertae are considered. In the case of 0727 - 115, it is pointed out that the nonuniformity of the swing rate and the apparent oscillations of the degree of polarization could be a consequence of relativistic aberration.

Item Type:	Journal Article
Publication:	Astrophysical Journal
Publisher:	Institute of physics
Additional Information:	Copyright for this article belongs to Institute of physics.
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	20 Feb 2010 08:14
Last Modified:	19 Sep 2010 05:55
URI:	http://eprints.iisc.ac.in/id/eprint/25650

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