The TOP-SCOPE Survey of PGCCs: PMO and SCUBA-2 Observations of 64 PGCCs in the Second Galactic Quadrant

Abstract

Abstract In order to understand the initial conditions and early evolution of star formation in a wide range of Galactic environments, we carried out an investigation of 64 Planck Galactic cold clumps (PGCCs) in the second quadrant of the Milky Way. Using the 13CO and C18O J = 1–0 lines and 850 μm continuum observations, we investigated cloud fragmentation and evolution associated with star formation. We extracted 468 clumps and 117 cores from the 13CO line and 850 μm continuum maps, respectively. We made use of the Bayesian distance calculator and derived the distances of all 64 PGCCs. We found that in general, the mass–size plane follows a relation of m ∼ r 1.67. At a given scale, the masses of our objects are around 1/10 of that of typical Galactic massive star-forming regions. Analysis of the clump and core masses, virial parameters, densities, and mass–size relation suggests that the PGCCs in our sample have a low core formation efficiency (∼3.0%), and most PGCCs are likely low-mass star-forming candidates. Statistical study indicates that the 850 μm cores are more turbulent, more optically thick, and denser than the 13CO clumps for star formation candidates, suggesting that the 850 μm cores are likely more appropriate future star formation candidates than the 13CO clumps.