Proposal code

w412

Proposal title

Jet/cloud interactions in 3C120

The

Investigators and their

Affiliations

P.I. José L. Gómez IAA, Granada (Spain)
Denise C. Gabuzda JIVE (Netherlands)
Alan P. Marscher, Svetlana G. Jorstad Boston University (USA)
Antonio Alberdi, Iv\'an Agudo IAA, Granada (Spain)

Proposal Abstract

Program BG073, and its continuation BG113, consisting of 22 and 43 GHz VLBA observations of 3C120, have represented, to our knowledge, the most through study of a relativsitic jet to date, completed with the highest resolution and polarization. Thanks to this extensive monitoring we have been able to trace superluminal components in 3C120 that exhibit cycles of brightening and fadin over timescales of months while showing rotation of the magnetic field. A possible explanation could be found in terms of an interaction with the external medium and free--free absorption by an ionized gas cloud to the near side of the jet. In order to test these hypotheses we propose further 5 GHz dual polarization VSOP observations to obtain a better determination of the rotation measure and opacity by comparison with dual polarization VLBA observations at 15, 22 and 43 GHz.

The full Cover Sheets (compressed post-script, typically 50kbytes) can be retrieved. Note that some 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 AO4 proposals were submitted in October 2000, and information such as affiliations and contact details has changed for some proposers since that time.