| Abstract : | Clouds more massive than about 10^5 M⊙ are potential sites of massive cluster formation. Studying the properties of such clouds in the early stages of their evolution offers an opportunity to test various cluster formation processes. We make use of CO, Herschel, and UKIDSS observations to study the global properties, physical structure, kinematics, and cluster formation potential of one such cloud, G148.24+00.41. Our results show the cloud to be of high mass (∼ 1.1 × 10^5 M⊙), low dust temperature (∼ 14.5 K), nearly circular (projected radius ∼ 26 pc), and gravitationally bound with a dense gas fraction of ∼ 18%.
The cloud consists of 4-5 filaments and shows the signature of longitudinal inflow towards the central clump through the filaments. The mass in the filaments ranges from ∼ 1 × 10^3 to 6.5 × 10^3 M⊙ and the total mass contained in the filaments is around 1.4 × 10^4 M⊙. The major filament is ~ 26 pc long, ~ 4.2 pc wide, and has a line mass of ~ 260 M⊙ pc^-1. Our analyses suggest that the central area of the cloud is actively forming protostars and is moderately fractal with a Q-value of ∼ 0.66. We find evidence of global mass segregation with a degree of mass segregation (Λ_???) ≈ 3.2. We discuss these results along with the structure of the cloud in the context of its cluster formation prospects and conclude that the cloud has the potential to form a massive cluster in the range ∼ 2000–3000 M⊙, but has to do so via dynamical processes such as conveyor-belt mode of cluster formation, where global convergence of both gaseous and stellar content may lead to a compact cluster. The converging flows towards the cluster centre are evident from the velocity gradient of gas in the filaments.
|
