Manash Samal (Graduate Institute of Astronomy, National Central University) Wen-Ping Chen (Graduate Institute of Astronomy, National Central University)
Molecular clouds associated with clusters of young stars are potential sites to study the onset of cluster formation. We make use of the Herschel, Spitzer, and UKIDSS observations of such a cloud, G148.02+00.18, to identify the embedded young stellar populations, thereby diagnosing the initial conditions of star and cluster formation. Located at 4.5 kpc from the sun, G148.02+00.18 is filamentary (aspect ratio ~ 3 ), massive ~10^5 Msun, and cold ~14 K, with a linear size ~17 pc. The spatial distribution of the YSOs suggest, cloud fragmentation has led to the formation of a chain of protoclusters along its spine. Each star cluster is different in the physical conditions and stellar contents, suggesting hierarchical star formation. Recent numerical simulations exhibit large-scale gas flows to the center of the molecular cloud's gravitational potential, following by merging of subclusters as a viable mechanism to make massive clusters in molecular clouds. The large reservoir of cold gas and chain of protoclusters identified in G148.02+00.18 makes it an excellent target for testing massive cluster formation theories.