On the early evolution of massive star clusters: the case of cloud D1
  and its embedded cluster in NGC 5253
  We discuss a theoretical model for the early evolution of massive star
clusters and confront it with the ALMA, radio and infrared observations of the
young stellar cluster highly obscured by the molecular cloud D1 in the nearby
dwarf spheroidal galaxy NGC 5253. We show that a large turbulent pressure in
the central zones of D1 cluster may cause individual wind-blown bubbles to
reach pressure confinement before encountering their neighbors. In this case
stellar winds are added to the hot shocked wind pockets of gas around
individual massive stars that leads them to meet and produce a cluster wind in
time-scales less than $10^5$ yrs. In order to inhibit the possibility of cloud
dispersal, or the early negative star formation feedback, one should account
for mass loading that may come, for example, from pre-main sequence (PMS)
low-mass stars through photo-evaporation of their proto-stellar disks. Mass
loading at a rate in excess of 8$\times 10^{-9}$ M$_{\odot}$ yr$^{-1}$ per each
PMS star is required to extend the hidden star cluster phase in this particular
cluster. In this regime, the parental cloud remains relatively unperturbed,
while pockets of molecular, photoionized and hot gas coexist within the star
forming region. Nevertheless, the most likely scenario for cloud D1 and its
embedded cluster is that the hot shocked winds around individual massive stars
should merge at an age of a few millions of years when the PMS star
proto-stellar disks vanish and mass loading ceases that allows a cluster to
form a global wind.
