A Collimated jet and an infalling-rotating disk in G192.16-3.84 traced by H2O maser emission

作者：Imai Hiroshi^*; Omodaka Toshihiro; Hirota Tomoya; Umemoto Tomofumi; Sorai Kazuo; Kondo Tetsuro

来源：Publications of the Astronomical Society of Japan, 2006, 58(5): 883-892.

• ISM : jets and outflows
• masers
• stars : formation
• stars : individual (G192.16-3.84)
• stars : mass accretion

We report on H2O masers associated with the massive-star forming region G192.16-3.84 observed with the new Japanese VLBI network at three epochs spanned for two months, which have revealed the three-dimensional kinematical structure of the whole H2O maser region in G192.16-3.84, containing two young stellar objects separated by similar to 1200AU. The maser spatio-kinematical structure has well persisted since previous observations, in which the masers are expected to be associated with a highly collimated bipolar jet and an infalling-rotating disk in the northern and southern clusters of H2O maser features, respectively. We estimated a jet expansion speed of similar to 100 km s(-1) and re-estimated the dynamical age of the whole jet to be 5.6 x 10(4) yr. We investigated the spatial distribution of the Doppler velocities during the previous and present observations and the relative proper motions of H2O maser features in the southern cluster, as well as the relative bulk motion between the two maser clusters. They are well explained by a model of an infalling-rotating disk with a radius of similar to 1000 AU and a central stellar mass of 5-10 M-circle dot, rather than by a model of a bipolar jet perpendicular to the observed CO outflow. Based on the derived H2O maser spatio-kinematical parameters, we discuss the formation mechanism of the massive young stellar objects and the outflow development in G192.16-3.84.

• 出版日期2006
• 单位中国科学院国家天文台