[Previous] | [Session 49] | [Next]
A. Wootten (NRAO), K. B. Marvel (AAS), M. Claussen (NRAO), B. Wilking (University of Missouri-St. Louis)
Water masers can be used to trace gas motions in a variety of sources including evolved stars and stars undergoing formation. Recent observations of the water masers associated with two young stellar objects, IRAS 05413-0104 (aka HH212) and S106FIR (Claussen et al 1998 ApJ 507, L79, Furuya et al 1999), have shown that water masers form in shocked gas associated with bipolar outflows from the central forming star. Recent observations (Imai et al. 1999, PASJ 51, 473) have led to the claim that the masers in IRAS 16293-2422 are associated with infalling, rotating gas associated with a circum-protostellar disk. We present proper motion measurements using four epochs of observation with the Very Long Baseline Array, which clearly show proper motions directed away from the central source in IRAS 16293-2422. These motions contradict the expected proper motions for an infalling-rotating gas model for this source.
The author(s) of this abstract have provided an email address for comments about the abstract: marvel@aas.org