CMB FOREGROUNDS & GALACTIC MAGNETIC FIELD


THE SURVEY

The Parkes Galactic Meridian Survey (PGMS) is a 5º wide strip to map the polarized synchrotron emission at all negative Galactic latitudes from the Galactic Plane down to the South Galactic Pole. Centred at the meridian l=254º, the 500 deg2 survey is carried out at the Parkes radiotelescope at a frequency of 2.3 GHz with 30 adjacent 8-MHz bands which enable Faraday Rotation studies.
The survey also includes a 10ºx10º enlargement at b = --35º (but with centre shifted to l=251º) that is the area covered by the 2003 flight of the BOOMERanG experiment.



SCIENCE GOALS

The scientific goal is two-fold:

- The Galactic synchrotron emission is one of the main contaminants of the CMB Polarization signal, especially for the weak B-Mode which promises to measure the primordial gravitational wave background left by the Inflation. The PGMS provides crucial information to clean the cosmic signal and to allow its measurement.
- The polarized synchrotron emission from the Galaxy is a powerful tool to probe the Galactic magnetism by measurements of RM (Rotation Measure). This is being quite well-studied in the Galactic plane, but little is known off plane. PGMS gives an insight into the Galactic magnetic field in the thick disc, halo, and at the disc-halo transition.


FACTS & PERFORMANCES

- Central frequency:        2.3 GHz
- Bandwidth:                  224 MHz
- FWHM:                         9’
σbeam:                           0.3 mK;
σRM  (b=[0º, --30º]):      10 rad/m2  (internal data only)
σRM  (b=[--30º, --90º]):     2 rad/m2  (with 1.4 GHz data)http://www.parkes.atnf.csiro.au/http://www.parkes.atnf.csiro.au/shapeimage_2_link_0shapeimage_2_link_1