The outer Galaxy presents an optimal setting for investigating molecular clouds and star formation in environments with low-metallicity. A total of 72 Galactic edge clouds were surveyed using the CO, (2--1) line with the IRAM, 30, m telescope, leading to the identification of 112 CO clumps within molecular clouds with linear resolutions of 0. 5--0. 9, pc. The parameters such as size, mass, surface density, and velocity dispersion of these CO clumps, derived from CO, (2--1) observations, exhibit ranges of 0. 6--3. 4, pc, 34--8250, M_⊙, 12--1025, M_⊙, pc-2, and -1, respectively. Over the galactocentric distance range of 14--23, kpc, no systematic variations are found in these parameters. The velocity dispersion--size relationship of the Galactic edge clumps is modeled as σ_̊m v, =, 0. 69 (±0. 03) R_ ̊m eff ^ 0. 36 (, indicating that turbulence is present within the Galactic edge clumps, similarly to observations in the inner Galactic disk clouds. Furthermore, the luminous mass--size relation of the Galactic edge clumps is described by M_̊m lum, =, 196 (±17) R_ ̊m eff ^, 2. 18, (, suggesting the average column density remains almost constant for clouds of different sizes. The virial parameters range from 0. 6 to 15. 3, with a median value of 2. 8, ±, 0. 6, suggesting that most clumps are gravitationally unbound. Furthermore, the virial parameters of our Galactic edge clumps show a decreasing trend with increasing galactocentric distances, described by an exponential relation α_̊m vir, =, 33. 0 (±, 10. 4), e -R_ ̊m g /6. 7 (, consistent with previous results.
Luo et al. (Wed,) studied this question.