Master thesis defense by Iason Michail Skretas

CO outflows from young stars in Cygnus-X: Exploring the connection of protostellar and extragalactic outflows

Molecular outflows are commonly detected originating from both protostellar and extragalactic sources. Separate studies of low-mass, high-mass and extragalactic sources have revealed similar scaling relations connecting the force carried by an outflow and the properties of the source that drives it.

The aim of this work is twofold, initially, to examine the effects of clustered star formation on the protostellar outflows and their scaling relations, and secondly, to explore the possibility that outflows varying in scale and energetics by many orders of magnitude are consistent with being launched by the same physical processes.

To that end, using high-angular resolution CO [J = 3-2] observations of 10 high-mass protostars in the Cygnus-X molecular cloud, obtained at the SubMilliMeter Array as part of the PILS Cygnus survey, the outflow force, i.e., the momentum ejection rate, is measured. In addition, an extended sample of protostellar and extragalactic outflow force measurements is assembled from existing literature, to allow for a direct comparison of their scaling relations.

A close agreement was found between the Cygnus-X sources and sources from the literature, strongly suggesting that, clustered star formation does not have a significant impact on the outflow energetics of protostars. In addition, the comparison of the protostellar and extragalactic sources revealed, with 95% confidence, that Class 0 protostars and extragalactic sources follow the same outflow force - bolometric luminosity correlation, thus offering strong indication that protostellar and extragalactic outflows have the same launch mechanism. The existence of such a mechanism would enable the development of a single universal outflow launch model, more observations are though required in order to verify this connection.

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