Ionization driven molecular outflow in K3-50A

¹ Leiden Observatory, PO Box 9513, 2300 RA Leiden, The Netherlands
e-mail: klaassen@strw.leidenuniv.nl
² European Southern Observatory, Karl Schwarzschild Str 2, 85748 Garching, Germany
³ Institut für Theoretische Physik, Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
⁴ Argelander Institut für Astronomie, Universität Bonn, Auf dem Hügel 71, 53121 Bonn, German

Received: 25 May 2012
Accepted: 3 July 2013

Abstract

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 H41α 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.