Infall and outflow motions in the high-mass star forming complex G9.62+0.19

Abstract

We present the results of a high resolution study with the Submillimeter Array towards the massive star forming complex G9.62+0.19. Three sub-mm cores are detected in this region. The masses are 13, 30 and 165 M$_{\sun}$ for the northern, middle and southern dust cores, respectively. Infall motions are found with HCN (4-3) and CS (7-6) lines at the middle core (G9.62+0.19 E). The infall rate is $4.3\times 10^{-3}{M}_{\odot }\cdot$yr${}^{-1}$. In the southern core, a bipolar-outflow with a total mass about 26 M$_{\sun}$ and a mass-loss rate of $3.6\times 10^{-5}{M}_{\odot }\cdot$yr${}^{-1}$ is revealed in SO ($8_7-7_7$) line wing emission. CS (7-6) and HCN (4-3) lines trace higher velocity gas than SO ($8_7-7_7$). G9.62+0.19 F is confirmed to be the driving source of the outflow. We also analyze the abundances of CS, SO and HCN along the redshifted outflow lobes. The mass-velocity diagrams of the outflow lobes can be well fitted by a single power law. The evolutionary sequence of the cm/mm cores in this region are also analyzed. The results support that UC~H{\sc ii} regions have a higher blue excess than their precursors.

50 pages, 16 figures, 4 tables