Radio continuum observations of IRAS sources associated with dense cores

Using the VLA, the continuum emission associated with IRAS sources embedded in dense cores was searched for at 6 cm. Two new sources, 04016 + 2610 in L1489 and 19243 + 2350 in L778, were detected. The embedded sources have low luminosity (L less than about 10 solar luminosities). As in other similar sources, if the emission is free-free, the stellar radiation cannot account for the observed ionization rate. Two models that have been proposed to explain the radio continuum emission from low-luminosity stars are those of (partially) ionized winds and shock-induced ionization. For the two new sources and a previously reported one (HL Tau), the associated molecular outflow is of modest power. It is shown that, under these conditions, these models, at least in their simplest versions, do not provide sufficient ionized gas. The nature of the radio continuum emission from low-luminosity young stars remains unexplained.