Dual differential polarimetry. A technique to recover polarimetric information from dual-polarization observations
Journal article, 2016

Current mm / submm interferometers, like the Atacama Large mm / submm Array (ALMA), use receivers that register the sky signal in a linear polarization basis. In the case of observations performed in full-polarization mode (where the cross-correlations are computed among all the polarization channels) it is possible to reconstruct the full-polarization brightness distribution of the observed sources, as long as a proper calibration of delay off sets and leakage among polarization channels can be performed. Observations of calibrators, preferably with some linear polarization, with a good parallactic angle coverage are usually needed for such a calibration. In principle, dual-polarization observations only allow us to recover the Stokes I intensity distribution of the sources, regardless of the parallactic angle coverage of the observations. In this paper, we present a novel technique of dual differential polarimetry that makes it possible to obtain information related to the full-polarization brightness distribution of the observed sources from dual-polarization observations. This technique is inspired in the Earth-rotation polarization synthesis and can be applied even to sources with complex structures.

techniques: interferometric

instrumentation: interferometers

techniques: polarimetric

Author

Ivan Marti-Vidal

Chalmers, Earth and Space Sciences, Onsala Space Observatory

Wouter Vlemmings

Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics

Sebastien Muller

Chalmers, Earth and Space Sciences, Onsala Space Observatory

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 593 Art no A61- A61

Subject Categories

Astronomy, Astrophysics and Cosmology

Roots

Basic sciences

DOI

10.1051/0004-6361/201628225

More information

Created

10/8/2017