The nature of the radio continuum sources embedded in the HH 7-11 region and its surroundings

Citation
Lf. Rodriguez et al., The nature of the radio continuum sources embedded in the HH 7-11 region and its surroundings, ASTROPH J S, 125(2), 1999, pp. 427-438
Citations number
50
Categorie Soggetti
Space Sciences
Journal title
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
ISSN journal
00670049 → ACNP
Volume
125
Issue
2
Year of publication
1999
Pages
427 - 438
Database
ISI
SICI code
0067-0049(199912)125:2<427:TNOTRC>2.0.ZU;2-P
Abstract
Using the Very Large Array, we have carried out sensitive radio continuum o bservations at 6 and 3.6 cm of the HH 7-11 region, detecting a total of 44 radio sources in the 8' x 8' region centered at this HH complex. The majori ty of these sources, at least 26 of them, are believed to be associated wit h young objects in the cloud. Among these sources are found candidates to p ower all the CO outflows observed in the region. For the first time, we det ect at centimeter wavelengths counterparts to the young objects IRAS 2A, IR AS 2B, ASR 51, ASR 7, MMS 2, and IRAS 4C, and to the foreground G2 IV star BD +30 degrees 547. There is a strong correlation between the far-infrared and millimeter sources reported previously and the centimeter sources discu ssed here. Most likely, this correlation results from the fact that young e mbedded 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 fr om the ionized flow. However, in two of the sources detected, the centimete r emission appears to have a significant contribution from heated dust. Two of the detected sources are time-variable, circularly polarized sources, a nd one of them is associated with a previously known T Tauri star. The resu lts of our study suggest that sensitive radio continuum studies of other ac tive star-forming regions could reveal a similar diversity of centimeter wa velength sources.