Star formation activity and the spatial distribution and mass
  segregation of dense cores in the early phases of star formation
  We examine the spatial distribution and mass segregation of dense molecular
cloud cores in a number of nearby star forming regions that span about four
orders of magnitude in star formation activity. We use an approach based on the
calculation of the minimum spanning tree, and for each region, we calculate the
structure parameter Q and the mass segregation ratio measured for various
numbers of the most massive cores. Our results indicate that the distribution
of dense cores in young star forming regions is very substructured and that it
is likely that this substructure will be imprinted onto the nascent clusters
that will emerge out of these clouds. With the exception of Taurus in which
there is nearly no mass segregation, we observe mild-to-significant levels of
mass segregation for the ensemble of the 6, 10, and 14 most massive cores in
Aquila, CrA, and W43, respectively. Our results suggest that the clouds' star
formation activity are linked to their structure, as traced by their population
of dense cores. We also find that the fraction of massive cores that are the
most mass segregated in each region correlates with the surface density of star
formation in the clouds. The Taurus region with low star-forming activity is
associated with a highly hierarchical spatial distribution of the cores (low Q
value) and the cores show no sign of being mass segregated. On the other
extreme, the mini-starburst region W43-MM1 has a higher Q that is suggestive of
a more centrally condensed structure and it possesses a higher fraction of
massive cores that are segregated by mass. While some limited evolutionary
effects might be present, we attribute the correlation between the star
formation activity of the clouds and their structure to a dependence on the
physical conditions that have been imprinted on them by the large scale
environment at the time they started to assemble
