Dense Cores in Perseus: The Influence of Stellar Content and Cluster
  Environment
  We present the chemistry, temperature, and dynamical state of a sample of 193
dense cores or core candidates in the Perseus Molecular cloud and compare the
properties of cores associated with young stars and clusters with those which
are not. The combination of our NH3 and CCS observations with previous
millimeter, sub-millimeter, and Spitzer data available for this cloud enable us
both to determine core properties precisely and to accurately classify cores as
starless or protostellar. The properties of cores in different cluster
environments and before-and-after star formation provide important constraints
on simulations of star-formation, particularly under the paradigm that the
essence of star formation is set by the turbulent formation of prestellar
cores. We separate the influence of stellar content from that of cluster
environment and find that cores within clusters have (1) higher kinetic
temperatures and (2) lower fractional abundances of CCS and NH3. Cores
associated with protostars have (1) slightly higher kinetic temperatures (2)
higher NH3 excitation temperatures), (3) are at higher column density, have (4)
slightly more non-thermal/turbulent NH3 linewidths, have (5) higher masses and
have (6) lower fractional abundance of CCS. We find that neither cluster
environment nor protostellar content makes a significant difference to the
dynamical state of cores as estimated by the virial parameter -- most cores in
each category are gravitationally bound. Overall, cluster environment and
protostellar content have a smaller influence on the properties of the cores
than is typically assumed, and the variation within categories is larger than
the differences between categories.
