Proposal code

v053

Proposal title

Polarization Variability of Intraday Variable Sources

The

Investigators and their

Affiliations

P.I. A. Witzel, T.P. Krichbaum MPIfR, Bonn, Germany
A. Kraus, S. Britzen MPIfR, Bonn, Germany
J.A. Zensus, A. Lobanov NRAO, Charlottesville
S.J. Wagner Landessternwarte Heidelberg, Germany

Proposal Abstract

About 30 0f extragalactic compact flat spectrum radio sources show intraday variability (IDV) with brightness temperatures of up to 10^{18-19} K in the radio. Correlated rapid variations of intensity and polarization indicate, that the emitting regions are smaller than typically 1 lightday (corresponding to microarcsecond sizes), making these objects (for which we have flux and VLBI-monitoring data since 1980) ideally suited for high angular resolution space-VLBI observations. We propose to image the sub-mas structure of a small sample of particularly well suited IDV-Quasars and IDV-BL Lacs in total and polarized flux. Repetition of these observations after a few days and after 1-2 weeks will allow to detect the theoretically expected structural variability (in I & P) in the sub-pc structures of IDV sources, putting hard constraints to our present understanding of the still 'mysterious' phenomenon of IDV.

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 AO1 proposals were submitted in November 1995, 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.