Multiple Sources toward the High-Mass Young Star S140 IRS 1
Abstract
S140 IRS 1 is a remarkable source where the radio source at the center of the main bipolar molecular outflow in the region is elongated perpendicular to the axis of the outflow, an orientation opposite to that expected if the radio source is a thermal jet exciting the outflow. We present results of 1.3 cm continuum and H2O maser emission observations made with the Very Large Array in its A configuration toward this region. In addition, we also present results of continuum observations at 7 mm and reanalyze observations at 2, 3.5, and 6 cm (previously published). IRS 1A is detected at all wavelengths, showing an elongated structure. Three water maser spots are detected along the major axis of the radio source IRS 1A. We have also detected a new continuum source at 3.5 cm (IRS 1C) located simeq0.6″ northeast of IRS 1A. The presence of these two young stellar objects (IRS 1A and 1C) could explain the existence of the two bipolar molecular outflows observed in the region. In addition, we have also detected three continuum clumps (IRS 1B, 1D, and 1E) located along the major axis of IRS 1A. We discuss two possible models to explain the nature of IRS 1A: a thermal jet and an equatorial wind.
- Publication:
-
The Astronomical Journal
- Pub Date:
- November 2007
- DOI:
- 10.1086/521926
- arXiv:
- arXiv:0708.0820
- Bibcode:
- 2007AJ....134.1870T
- Keywords:
-
- ISM: individual: S140 IRS 1;
- ISM: jets and outflows;
- masers;
- stars: formation;
- stars: pre-main sequence;
- Astrophysics
- E-Print:
- 17 pages, 4 figures, to be published in AJ