A Rotating Molecular Disk and Ionized Outflow in K3-50A
Session 84 -- Star Forming Clouds
Display presentation, Wednesday, 11, 1995, 9:20am - 6:30pm

## [84.17] A Rotating Molecular Disk and Ionized Outflow in K3-50A

C. De Pree (NRAO-VLA, UNC Chapel Hill), T. Geballe (JAC), W. M. Goss (NRAO-VLA), D. Mehringer (UIUC), G. Cecil (UNC-Chapel Hill)

The bipolar HII region K3-50A has been observed in the radio recombination lines (RRLs) H92$\alpha$ and He92$\alpha$ with the Very Large Array, and in the Br$\alpha$ recombination line with the United Kingdom Infrared Telescope. The spatial and spectral resolutions of the two observations are 2.3\arcsec~and 7 km s$^{-1}$ for the RRLs and 1.3\arcsec~and 19 km s$^{-1}$ for Br$\alpha$. Velocity gradients consistent with rotation ($\sim$20 km s$^{-1}$ pc$^{-1}$) and an outflow parallel to the rotation axis ($\sim$150 km s$^{-1}$ pc$^{-1}$) are observed in the ionized gas. Furthermore, Br$\alpha$ emission is detected from regions (perpendicular to the ionized outflow) where there is no radio continuum emission. This Br$\alpha$ emission is most likely due to IR photons which are scattered from dust in a disk that directs the outflow. This hypothesis is supported by existing interferometric HCO$^+$ (J=1$\rightarrow$0) observations of the surrounding molecular material (Vogel $\&$ Welch 1983) which appear to show a rotating, flattened molecular disk. Together, these data allow a self-consistent picture of K3-50A to be constructed in which a rotating molecular disk directs a bipolar ionized outflow.