Previous abstract Next abstract

Session 7 - Molecular Clouds.
Display session, Wednesday, January 07
Exhibit Hall,

[7.18] Circularly polarized radio emission from an X-ray protostar

E. D. Feigelson (Penn State), L. Carkner (Penn State), B. A. Wilking (Missouri-St. Louis)

IRS 5, an embedded young stellar object in the nearby Corona Australis molecular cloud, was recently detected as an X-ray source with the ASCA and ROSAT satellites. We report here the detection of circularly polarized continuum emission from IRS 5 at centimeter wavelengths with the Very Large Array. Already known to be a highly variable radio source, the polarization fraction is seen to range from V/I \simeq 10% to \simeq 37% on a day timescale. This demonstrates that radio emission from protostars, previously attributed to ionized thermal outflows, can sometimes arise instead from nonthermal processes; i.e. gyrosynchrotron emission from particles accelerated in situ by magnetic reconnection flares. Together with the X-ray data and indications of MeV particles in the solar nebula obtained from meteoritic materials, it contributes to the growing evidence for high energy processes during the earliest stages of low mass star formation.

Program listing for Wednesday