SF-08-0006

Formation and environment of multiple protostellar systems in Perseus

Nadia M. Murillo, Nami Sakai, Daniel Harsono

The range of separations and configurations of multiple protostellar systems raise the question of what factors influence the formation of these systems. Models have probed the effect of several factors on the formation of multiple protostellar systems, but few observational constraints are available to test the modeled scenarios. In addition to the arrangement of protostellar components in multiple systems, the distribution of molecular gas reveals the dynamical processes within the system. Observations show physical and chemical variation among the components of multiple protostellar systems. However, the reason for this variation is not well understood, and few physico-chemical models of multiple protostellar systems have been done. A survey of protostellar systems in Perseus including single and multiple protostars located in clustered and non-clustered regions, spanning evolutionary stages from Class 0 to Class II, as well as starless cores, is used to study these questions. Using single dish observations together with ALMA ACA and SMA observations, the gas from molecular cloud scales (>10000 AU) down to the inner envelope scales (?1000 AU) is probed. Gas temperature, density, and mass are derived from the observations, and compared to multiplicity, evolutionary stage, region, bolometric luminosity from the SED, and envelope mass from 850 μm continuum. Molecular cloud gas temperature maps and gas kinematics are compared with the location of protostellar systems, and between clustered and non-clustered regions. The results of this survey indicate that gas temperature and density are not related to multiplicity, but rather the availability of gas mass is key in multiple star formation. Comparison of the results from the Perseus survey with other regions and mass ranges provides a broader view of the factors that influence multiple star formation and their molecular gas environment.