Distribution and motion of the water masers near IRAS 05413-0104

Citation
Mj. Claussen et al., Distribution and motion of the water masers near IRAS 05413-0104, ASTROPHYS J, 507(1), 1998, pp. L79-L82
Citations number
20
Categorie Soggetti
Space Sciences
Journal title
ASTROPHYSICAL JOURNAL
ISSN journal
0004637X → ACNP
Volume
507
Issue
1
Year of publication
1998
Part
2
Pages
L79 - L82
Database
ISI
SICI code
0004-637X(19981101)507:1<L79:DAMOTW>2.0.ZU;2-8
Abstract
We have used the NRAO Very Long Baseline Array to image water masers associ ated with the low-luminosity, young stellar object (YSO) IRAS 05413-0104 at four epochs over a period of 10 weeks. The maser images show the detail of a symmetric, jetlike structure about 300 mas in extent. The 23 degrees +/- 2 degrees position angle of the maser spot distribution is in excellent ag reement with measured position angles for the observed larger scale H-2 and SiO emission distributions; radial velocities are in agreement with SiO me asurements showing redshifted gas to the southwest and blueshifted gas to t he northeast. We have detected proper motions of numerous maser spots avera ging 30 +/- 12 mas yr(-1), implying space velocities of 64 +/- 27 km s(-1) for a source distance of 450 pc. Some masers are located within a projected distance of 40 AU of the origin of expansion, the assumed position of the central source, suggesting that jet formation and acceleration takes place within this radius of the YSO. We compute an inclination of the outflow sys tem to the plane of the sky of 4 degrees, based on the relative magnitude o f the proper motions and radial velocities of the masers. VLBI observations of water masers in YSOs are clearly demonstrated to be interesting and com petitive probes of the kinematics of the gas in YSO jets.