Ionization driven molecular outflow in K3-50A

Context. Whether high mass stars continue to accrete material beyond the formation of an HII region is still an open question. Ionized infall and outflow have been seen in some sources, but their ties to the surrounding molecular gas are not well constrained. Aims: We aim to quantify the ionized and molecular gas dynamics in a high mass star forming region (K3-50A) and their interaction. Methods: We present CARMA observations of the 3mm continuum, HCO+ and H41� emission, and VLA continuum observations at 23 GHz and 14.7 GHz to quantify the gas and its dynamics in K3-50A. Results: We find large scale dynamics consistent with previous observations. On small scales, we find evidence for interaction between the ionized and molecular gas that suggests the ionized outflow is entraining the molecular one. This is the first time such an outflow entrained by photo ionized gas has been observed. Conclusions: Accretion may be ongoing in K3-50A because an ionized bipolar outflow is still being powered, which is in turn entraining part of the surrounding molecular gas. This outflow scenario is similar to that predicted by ionization feedback models. DOI: https://doi.org/10.1051/0004-6361/201219683 Posted at the Zurich Open Repository and Archive, University of Zurich ZORA URL: https://doi.org/10.5167/uzh-90742 Accepted Version Originally published at: Klaassen, P D; Galván-Madrid, R; Peters, T; Longmore, S N; Maercker, M (2013). Ionization driven molecular outflow in K3-50A. Astronomy and Astrophysics, 556:A107. DOI: https://doi.org/10.1051/0004-6361/201219683 ar X iv :1 30 7. 10 42 v1 [ as tr oph .G A ] 3 J ul 2 01 3 Astronomy & Astrophysics manuscript no. k350 c © ESO 2013