25 March 2008, 12:30pm

Radio Polarization as a Tool for Exploring the Milky Way

Tom Landecker

Dominion Radio Astrophysical Observatory
National Research Council Canada
Penticton, B.C.

Magnetic fields in the Galaxy are a significant reservoir of energy and
they must play a central role in interstellar processes. Imaging of the
polarized Galactic radio emission is an important tool in unravelling
the structure and strength of the field.

We have recently completed a survey of polarized emission at 1.4 GHz
from the Galactic plane. Combination of data from the DRAO Synthesis
Telescope, the Effelsberg 100-m Telescope and the DRAO 26-m Telescope
gives full sampling of polarized emission from the largest structures
down to the resolution limit, of the order of 1 arcminute. With 17
million independent data points, this is the largest survey ever made
of extended polarized emission.

I will describe the techniques developed for acquiring and processing
this wide-field polarimetric survey and for combining single-antenna
and aperture-synthesis datasets. I will discuss preliminary
interpretations of many of the details seen in the images.

The future of this subject lies in wideband polarimetry with many
frequency channels. I will describe new data acquisition and processing
techniques, and will outline plans for surveys of the whole sky, north
and south, using large single-antenna radio telescopes.