The Submillimeter Array

Polarization Studies

Polarization observations with the SMA are currently carried out using quarter-wave plates that convert each linear feed of each receiver to a switchable circular feed. To obtain all four stokes parameters, each antenna is switched between polarizations in a coordinated sequence to sample quickly all four combinations of circular polarizations on each baseline. Plates are available with central frequencies near 230/690, 342 and 240/400 GHz.

Polarization Studies

Jim Moran

Ram Rao, Ya-Wen Tang

Other Collaborators:
Dan Marrone, Meredith Hughes, Josep Miguel Girart

Image of Pluto

SMA map of the polarized emission in Stokes-1 in NGC 1333 IRAS4A at a resolution of 1.6" x 1.0". In this image the contours represent the total intensity of Stokes 1 of the dust continuum while the color image is the polarized flux density. The lengths of the vectors represent fractional polarization and the direction is the position angle of polarization. At the peak of the polarized flux density, the fractional polarization is around 8%. (Rao et al 2006).