Observing Turbulent Fragmentation in Simulations: Predictions for CARMA and ALMA

TL;DR

This paper uses synthetic interferometric observations to study turbulent fragmentation in star-forming cores, showing how CARMA and ALMA can detect early multiplicity and substructure despite observational limitations.

Contribution

It provides the first detailed predictions of how CARMA and ALMA observations can reveal turbulent fragmentation and early stellar multiplicity in starless and protostellar cores.

Findings

CARMA observations are likely featureless at early stages for starless cores.

ALMA can detect substructure and early multiplicity more effectively.

Interferometric filtering reduces observable core substructure.

Abstract

Determining the initial stellar multiplicity is a challenging problem since protostars are faint and deeply embedded at early times; once formed, multiple protostellar systems may significantly dynamically evolve before they are optically revealed. Interferometers such as CARMA and ALMA make it possible to probe the scales at which turbulent fragmentation occurs in dust continuum emission, potentially constraining early stellar multiplicity. In this Letter we present synthetic observations of starless and protostellar cores undergoing fragmentation on scales of a few thousand AU to produce wide binary systems. We show that interferometric observations of starless cores by CARMA should be predominantly featureless at early stages, although wide protostellar companions should be apparent. The enhanced capabilities of ALMA improve the detection of core morphology so that it may be possible to detect substructure at earlier times. In either case, spatial filtering from interferometry reduces the observed core substructure and often eradicates traces of existing filamentary morphology on scales down to 0.025 pc. However, some missing structure may be recaptured by combining data from the ALMA full science and Atacama compact arrays.