High Angular Resolution Observations of Four Candidate BLAST High-Mass Starless Cores

TL;DR

This study uses high-resolution ammonia observations to analyze four candidate high-mass starless cores identified by BLAST, revealing their cold, quiescent, and filamentary nature, indicative of an early evolutionary stage.

Contribution

It provides detailed high-angular resolution data on four candidate high-mass starless cores, highlighting their cold temperatures and internal velocity structures, which were previously uncharacterized.

Findings

Cores are cold with temperatures below 14K.

Cores exhibit filamentary and clumpy structures.

Cores show significant internal velocity substructure.

Abstract

We discuss high-angular resolution observations of ammonia toward four candidate high-mass starless cores (HMSCs). The cores were identified by the Balloon-borne Large Aperture Submillimeter Telescope (BLAST) during its 2005 survey of the Vulpecula region where 60 compact sources were detected simultaneously at 250, 350, and 500 micron. Four of these cores, with no IRAS-PSC or MSX counterparts, were observed with the NRAO Very Large Array (VLA) in the NH3(1,1) and (2,2) spectral lines. Our observations indicate that the four cores are cold (Tk <~ 14K) and show a filamentary and/or clumpy structure. They also show a significant velocity substructure within ~1km/s. The four BLAST cores appear to be colder and more quiescent than other previously observed HMSC candidates, suggesting an earlier stage of evolution.