Proposal code

w043

Proposal title

High resolution imaging of the helical jet in the BL Lac 1803+784

The

Investigators and their

Affiliations

P.I. T.P. Krichbaum MPIfR, Bonn, Germany
A. Witzel MPIfR, Bonn, Germany
J.A. Zensus MPIfR, Bonn, Germany
S. Britzen NFRA, Dwingeloo, The Netherlands

Proposal Abstract

{\small Ground based 90/18 cm VLBI maps of the BLLac 1803+78 show a complex jet bending to the north, while VLA and WSRT maps reveal a north-south oriented structure, misaligned with the VLBI jet by ~ 80^\circ. On sub-mas to mas-scales the inner jet components move along a three-dimensionally bent and probably helical path. With the proposed experiment we intend to follow the helical oscillations of the jet axis towards larger core separations in order to relate the jet bending seen in the inner jet with the strong curvature seen further out. Since the amplitude of the tranverse oscillations of the jet axis lie below the resolution limit for ground based VLBI at 18 cm, space-VLBI will give us the unique opportunity to study this effect also at long cm-wavelengths and large core separations. With this we will be able to test the model of conical helical jets proposed e.g. by Conway and Murphy 1993, and Steffen et al. 1995. }

The full Cover Sheets (compressed post-script, typically 50kbytes) can be retrieved. Note that many proposals were reduced in extent by the Scientific Review Committee (e.g. by reducing the number of experiments), however the Cover Sheets contain the full proposal as submitted. Also note that AO2 proposals were submitted in May 1998, and information such as affiliations and contact details has changed for some proposers since that time. The Cover Sheets (and the details on this page, which were derived from the Cover Sheets) may therefore have changed.