Follow-up observations toward Planck cold clumps with ground-based radio telescopes

TL;DR

This study uses ground-based radio telescopes to observe Planck cold clumps, revealing their physical states and identifying dense starless clumps as potential prestellar objects, thus advancing understanding of early star formation stages.

Contribution

It provides a large sample of Planck cold clumps observed with ground-based telescopes, highlighting their properties and identifying dense starless clumps as promising prestellar candidates.

Findings

Most PCCs are in early star formation phases.

Some PCCs are associated with protostars and outflows.

Hundreds of starless dense clumps identified as potential prestellar objects.

Abstract

The physical and chemical properties of prestellar cores, especially massive ones, are still far from being well understood due to the lack of a large sample. The low dust temperature ($<$14 K) of Planck cold clumps makes them promising candidates for prestellar objects or for sources at the very initial stages of protostellar collapse. We have been conducting a series of observations toward Planck cold clumps (PCCs) with ground-based radio telescopes. In general, when compared with other star forming samples (e.g. infrared dark clouds), PCCs are more quiescent, suggesting that most of them may be in the earliest phase of star formation. However, some PCCs are associated with protostars and molecular outflows, indicating that not all PCCs are in a prestellar phase. We have identified hundreds of starless dense clumps from the mapping survey with the Purple Mountain Observatory (PMO) 13.7-m telescope. Follow-up observations suggest that these dense clumps are ideal targets to search for prestellar objects.