The Nature of the Radio Continuum Sources Embedded in the HH 7–11 Region and Its Surroundings

Abstract

Using the Very Large Array, we have carried out sensitive radio continuum observations at 6 and 3.6 cm of the HH 7-11 region, detecting a total of 44 radio sources in the 8' × 8' region centered at this HH complex. The majority of these sources, at least 26 of them, are believed to be associated with young objects in the cloud. Among these sources are found candidates to power all the CO outflows observed in the region. For the first time, we detect at centimeter wavelengths counterparts to the young objects IRAS 2A, IRAS 2B, ASR 51, ASR 7, MMS 2, and IRAS 4C, and to the foreground G2 IV star BD +30°547. There is a strong correlation between the far-infrared and millimeter sources reported previously and the centimeter sources discussed here. Most likely, this correlation results from the fact that young embedded stars systematically have ionized outflows. Under these assumptions, the far-infrared and millimeter emission will originate from dust heated in the surroundings of the star, while the centimeter emission will come from the ionized flow. However, in two of the sources detected, the centimeter emission appears to have a significant contribution from heated dust. Two of the detected sources are time-variable, circularly polarized sources, and one of them is associated with a previously known T Tauri star. The results of our study suggest that sensitive radio continuum studies of other active star-forming regions could reveal a similar diversity of centimeter wavelength sources.