The Spatial Evolution of Young Massive Clusters I. A New Tool to
  Quantitatively Trace Stellar Clustering
  Aims. To present the new novel statistical clustering tool 'INDICATE' which
assesses and quantifies the degree of spatial clustering of each object in a
dataset, discuss its applications as a tracer of morphological stellar features
in star forming regions, and to look for these features in the Carina Nebula
(NGC 3372).
  Results. We successfully recover known stellar structure of the Carina
Nebula, including the 5 young star clusters in this region. Four sub-clusters
contain no, or very few, stars with a degree of association above random which
suggests they may be fluctuations in the field rather than real clusters. In
addition we find: (1) Stars in the NW and SE regions have significantly
different clustering tendencies, which is reflective of differences in the
apparent star formation activity in these regions. Further study is required to
ascertain the physical origin of the difference; (2) The different clustering
properties between these two regions are even more pronounced for OB stars; (3)
There are no signatures of classical mass segregation present in the SE region
- massive stars here are not spatially concentrated together above random; (4)
Stellar concentrations are more frequent around massive stars than typical for
the general population, particularly in the Tr14 cluster; (5) There is a
relation between the concentration of OB stars and the concentration of (lower
mass) stars around OB stars in the centrally concentrated Tr14 and Tr15, but no
such relation exists in Tr16. We conclude this is due to the highly
sub-structured nature of Tr16.
  Conclusions. INDICATE is a powerful new tool employing a novel approach to
quantify the clustering tendencies of individual objects in a dataset within a
user-defined parameter space. As such it can be used in a wide array of data
analysis applications.
