Magnetic fields in young stellar objects

The formation of stars and planets is accompanied not only by inflows of matter, as one might expect, but also by outflows. These outflows take the form of supersonic and highly collimated jets that can stretch for several light years and extend even beyond the parent molecular cloud. Although the precise mechanism by which jets from young stars are produced is uncertain, it is believed that they are generated and focused through the action of magnetic fields. Moreover while we know most of their parameters, such as density, ionization fraction, velocity, etc., pinning down the strength and direction of their fields has proven notoriously difficult. Here I examine the major role radio astronomy can play in determining their magnetic field parameters and highlight some recent very surprizing results at low frequencies that suggest outflows may help ionize the parent cloud.