On the Scarcity of Dense Cores ( n > 10 5 cm −3 ) in High-latitude Planck Galactic Cold Clumps

Xu, Fengwei, Wang, Ke, Liu, Tie, Eden, David, Liu, Xunchuan, Juvela, Mika, He, Jinhua, Johnstone, Doug, Goldsmith, Paul et al (2024) On the Scarcity of Dense Cores ( n > 10 5 cm −3 ) in High-latitude Planck Galactic Cold Clumps. Astrophysical Journal Letters, 963 (1). ISSN 2041-8205

[thumbnail of VOR]
PDF (VOR) - Published Version
Available under License Creative Commons Attribution.


Official URL: https://doi.org/10.3847/2041-8213/ad21e6


High-latitude (∣b∣ > 30°) molecular clouds have virial parameters that exceed 1, but whether these clouds can form stars has not been studied systematically. Using JCMT SCUBA-2 archival data, we surveyed 70 fields that target high-latitude Planck Galactic cold clumps (HLPCs) to find dense cores with density of 105–106 cm−3 and size of <0.1 pc. The sample benefits from both the representativeness of the parent sample and its coverage of the densest clumps at the high column density end (>1 × 1021 cm−2). At an average rms of 15 mJy beam−1, we detected Galactic dense cores in only one field, G6.04+36.77 (L183) while also identifying 12 extragalactic objects and two young stellar objects. Compared to the low-latitude clumps, dense cores are scarce in HLPCs. With synthetic observations, the densities of cores are constrained to be n c ≲ 105 cm−3 should they exist in HLPCs. Low-latitude clumps, Taurus clumps, and HLPCs form a sequence where a higher virial parameter corresponds to a lower dense-core detection rate. If HLPCs were affected by the Local Bubble, the scarcity should favor turbulence-inhibited rather than supernova-driven star formation. Studies of the formation mechanism of the L183 molecular cloud are warranted.

Repository Staff Only: item control page