•Polarization, Faraday
Rotation
•Synchrotron radiation is
highly polarized perpendicular to the direction of B. Why?
•Linear polarized wave is
rotated as it moves through ionized gas:
–Δθ = 4.64x106 nt Bp Lλ2 where n is the cgs density of thermal electrons, B
is the parallel magnetic
field in Gauss, L is the length in kpc, and the wavelength is in
cm. Measure at two wavelengths to correct for and
measure the Faraday
rotation. Can be helpful when
looking at
two radio lobes (e.g., which is foreground).