A tale of two clusters: dynamical history determines disc survival in
  Tr14 and Tr16 in the Carina Nebula
  Understanding how the birthplace of stars affects planet-forming discs is
important for a comprehensive theory of planet formation. Most stars are born
in dense star-forming regions where the external influence of other stars,
particularly the most massive stars, will affect the survival and enrichment of
their planet-forming discs. Simulations suggest that stellar dynamics play a
central role in regulating how external feedback affects discs, but comparing
models to observations requires an estimate of the initial stellar density in
star-forming regions. Structural analyses constrain the amount of dynamical
evolution a star-forming region has experienced; regions that maintain
substructure and do not show mass segregation are likely dynamically young, and
therefore close to their birth density. In this paper, we present a structural
analysis of two clusters in the Carina Nebula, Tr14 and Tr16. We show that
neither cluster shows evidence for mass segregation or a centrally concentrated
morphology, suggesting that both regions are dynamically young. This allows us
to compare to simulations from Nicholson et al. (2019) who predict disc
survival rates in star-forming regions of different initial densities. The
surviving disc fractions in Tr14 and Tr16 are consistent with their predictions
(both are $\sim 10$%), supporting a growing body of evidence that the
star-forming environment plays an important role in the survival and enrichment
of protoplanetary discs.
