Proposal code

w054

Proposal title

DISTINGUISHING BETWEEN MODELS OF RADIO CORE GEOMETRY

The

Investigators and their

Affiliations

P.I. Dayton L.Jones Jet Propulsion Laboratory, Caltech, USA
David W.Murphy, Steven J.Tingay, Jet Propulsion Laboratory, Caltech, USA
Robert A.Preston, & David L.Meier Jet Propulsion Laboratory, Caltech, USA

Proposal Abstract

We propose to observe the compact, morphologically simple source AO 0235+164 with VSOP and several large ground telescopes, particularly Arecibo. The VSOP-Arecibo baseline, by far the most sensitive available, will cover all projected spacings from less than an Earth diameter out to about 26,000 km, nearly the maximum possible. The resulting high signal to noise ratio on baselines longer than an Earth diameter will allow us to distinguish between Gaussian, optically thin sphere, and optically thick sphere (uniform disk) models of the core geometry. Gaussian models are frequently used when determining core brightness temperatures, for example, but these may not be the most appropriate models. The difference in brightness temperature derived using different models can be large -- nearly a factor of 3 between Gaussians and uniform disks. AO 0235+164 should be well described by a single component model.

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.