Young stellar clusters in the Rosette molecular cloud. Arguments against
  triggered star formation
  The Rosette complex is a well studied region of the galactic plane which
presents the apparent characteristics of a triggered star forming region. This
is however still debated as no strong evidence corroborates this statement. We
focus on characterizing the young stellar population in the Rosette complex to
improve our understanding of the processes that regulate the star formation in
this region. We propose an original method that relies on the joint analysis of
the star color and density in the near-infrared. It leads to mapping the
molecular cloud spatial distribution and detecting the embedded clusters with
their characterization in terms of member number and age estimation. We have
identified 13 clusters, 2 of which are new discoveries, and we estimate that
the total number of young stellar objects in the Rosette ranges between 4000
and 8000 members. We find that the age distribution of the young clusters is
not consistent with a general triggered scenario for the star formation in this
molecular cloud. This study proves that the Rosette complex evolution is not
governed by the influence of its OB star population. It suggests that the
simple morphological appearance of an active region is not sufficient to
conclude much about the triggering role in the star formation process. Our
method of constraining the cluster properties using UKIDSS and WISE data has
proven efficient, and studies of other regions of the galactic plane would
definitely benefit from this approach.
