A study of Galactic Plane Planck Galactic Cold Clumps observed by SCOPE and the JCMT Plane Survey

TL;DR

This study analyzes the physical properties of Galactic Cold Clumps in the Plane using JCMT and SCOPE surveys, revealing they are colder, denser, and less active in star formation than other Galactic sources.

Contribution

It provides a detailed characterization of PGCCs in the Galactic Plane, highlighting their distinct physical and star-forming properties compared to other Galactic sources.

Findings

PGCCs are colder and denser than non-PGCC sources.

Star formation activity in PGCCs is significantly lower.

PGCCs represent a distinct population in the Galactic Plane.

Abstract

We have investigated the physical properties of Planck Galactic Cold Clumps (PGCCs) located in the Galactic Plane, using the JCMT Plane Survey (JPS) and the SCUBA-2 Continuum Observations of Pre-protostellar Evolution (SCOPE) survey. By utilising a suite of molecular-line surveys, velocities and distances were assigned to the compact sources within the PGCCs, placing them in a Galactic context. The properties of these compact sources show no large-scale variations with Galactic environment. Investigating the star-forming content of the sample, we find that the luminosity-to-mass ratio (L/M) is an order of magnitude lower than in other Galactic studies, indicating that these objects are hosting lower levels of star formation. Finally, by comparing ATLASGAL sources that are associated or are not associated with PGCCs, we find that those associated with PGCCs are typically colder, denser, and have a lower L/M ratio, hinting that PGCCs are a distinct population of Galactic Plane sources.