Stellar clusterings around "Isolated" Massive YSOs in the LMC
  Observations suggest that there is a significant fraction of O-stars in the
field of the Milky Way that appear to have formed in isolation or in low mass
clusters ($<$100 $M_\odot$). The existence of these high-mass stars that
apparently formed in the field challenges the generally accepted paradigm,
which requires star formation to occur in clustered environments. In order to
understand the physical conditions for the formation of these stars, it is
necessary to observe isolated high-mass stars while they are still forming.
With the $Hubble$ $Space$ $Telescope$, we observe the seven most isolated
massive ($>$8 $M_\odot$) young stellar objects (MYSOs) in the Large Magellanic
Cloud (LMC). The observations show that while these MYSOs are remote from other
MYSOs, OB associations, and even from known giant molecular clouds, they are
actually not isolated at all. Imaging reveals $\sim$100 to several hundred
pre--main-sequence (PMS) stars in the vicinity of each MYSO. These previously
undetected PMS stars form prominent compact clusters around the MYSOs, and in
most cases they are also distributed sparsely across the observed regions.
Contrary to what previous high-mass field star studies show, these observations
suggest that high-mass stars may not be able to form in clusters with masses
less than 100 $M_\odot$. If these MYSOs are indeed the best candidates for
isolated high-mass star formation, then the lack of isolation is at odds with
random sampling of the IMF. Moreover, while isolated MYSOs may not exist, we
find evidence that isolated clusters containing O-stars can exist, which in
itself is rare.
