SPATIAL-DISTRIBUTION OF EMBEDDED CLUSTERS IN THE ROSETTE-MOLECULAR-CLOUD - IMPLICATIONS FOR CLUSTER FORMATION

We have imaged a similar to 0.7 deg(2) region of the Rosette Molecular Cloud (RMC) using the simultaneous quad infrared imaging device on th e Kitt Peak National Observatory 1.3 m telescope. The region observed covers most of the (CO)-C-13 emission detected by Blitz & Stark, as we ll as the majority of the IRAS point sources listed by Cox, Deharveng, & Leene and Williams, Blitz, & Stark. In this paper, we report the de tection of seven young embedded clusters in the RMC, five of which wer e previously unknown. All seven clusters are associated with IRAS sour ces and with molecular ((CO)-C-13) clumps (Williams et al.), although not all IRAS sources or molecular clumps are associated with clusters. The molecular clumps that contain clusters are among the most massive clumps in the cloud, indicating that high-mass regions are required f or the formation of clusters. However, the majority of massive (CO)-C- 13 clumps in the RMC are not associated with embedded clusters, sugges ting that conditions other than high mass, such as high density, are n eeded for cluster formation. The spatial location of most of the clust ers suggests that cluster formation may be triggered by the ionization fronts from the nearby H II region associated with NGC 2244. However, triggered star formation cannot explain the presence of all of the cl usters, suggesting that more than one mechanism may be at work forming clusters in this cloud.