THE SYNCHROTRON JET FROM THE H-2O MASER SOURCE IN W3(OH)

摘要

We report results of sensitive Very Large Array observations of the 8.4 GHz continuum emission associated with the TW object, a luminous young star located at the center of expansion of the H2O masers in the W3(OH) region. The source has a radio spectral index of --0.6 and exhibits a sinuous double-sided morphology; these are characteristics of a synchrotron jet. No significant changes are seen in the jet morphology in observations separated by 5l0 days. The inhomogeneous synchrotron model proposed by Reid et al., which is based on the spectrum and size variation with observing frequency, correctly predicts the flux density profile of the radio emission. Secondary radio continuum features located at the extreme of the H_2O maser distribution may mark the location of strong shocks and deeply embedded Herbig-Haro objects or additional young stellar objects in the W3(OH) cluster. Several more compact sources are identified in the region, some of which are highly variable. These may be low-mass pre--main-sequence stars with magnetic activity.