Connecting Galactic and extragalactic outflows: From the Cygnus-X cluster to active galaxies

Abstract

Molecular outflows are often detected originating from both protostellar and extragalactic sources. Studies of low-mass, isolated high-mass, and extragalactic sources reveal scaling relations connecting the force carried by an outflow and the properties of the source that drives it. The aim of this work is to examine the effects of clustered star formation on the protostellar outflows and their scaling relations and to explore the possibility that outflows varying greatly scale and energetics are consistent with being launched by the same physical processes. High-angular resolution CO J = 3-2 observations were used of ten high-mass protostars in the Cygnus-X molecular cloud, obtained at the SMA as part of the PILS-Cygnus survey. From these data, the outflow force was measured. In addition, an extended sample of protostellar and extragalactic outflow-force measurements was assembled from existing literature to allow for a direct comparison of the scaling relations of the two types of outflows. Molecular outflows were detected originating from all ten sources of the PILS-Cygnus survey, and their outflow forces are found in close agreement with measurements from the literature. The comparison of the protostellar and extragalactic sources reveals, with 95\% confidence, that Class 0 protostars and extragalactic sources follow the same outflow force--bolometric luminosity correlation. The close agreement between the Cygnus-X sources and sources of similar envelope mass and bolometric luminosity suggests that clustered star formation has no significant effect on protostellar outflows. We find a strong indication that protostellar and extragalactic outflows are consistent with having a similar launch mechanism. The existence of such a mechanism would enable the development of a single universal outflow launch model, although more observations are required in order to verify this connection.