The low-mass population in the young cluster Stock 8: Stellar properties
  and Initial Mass Function
  The evolution of HII regions/supershells can trigger a new generation of
stars/clusters at their peripheries, with environmental conditions that may
affect the initial mass function, disk evolution and star formation efficiency.
In this paper we study the stellar content and star formation processes in the
young cluster Stock 8, which itself is thought to be formed during the
expansion of a supershell. We present deep optical photometry along with JHK
and 3.6, 4.5 {\mu}m photometry from UKIDSS and Spitzer-IRAC. We use multi-color
criteria to identify the candidate young stellar objects in the region. Using
evolutionary models, we obtain a median log(age) of ~6.5 (~3.0 Myr) with an
observed age spread of ~0.25 dex for the cluster. Monte Carlo simulations of
the population of Stock 8, based on estimates for the photometric uncertainty,
differential reddening, binarity, and variability, indicate that these
uncertainties introduce an age spread of ~0.15 dex. The intrinsic age spread in
the cluster is ~0.2 dex. The fraction of young stellar objects surrounded by
disk is ~35%. The K-band luminosity function of Stock 8 is similar to that of
the Trapezium cluster. The IMF of Stock 8 has a Salpeter- like slope at >0.5
Msun and the IMF flattens and peaks at ~0.4 Msun, below which declines into the
substellar regime. Although Stock 8 is surrounded by several massive stars,
there seems to be no severe environmental effect in the form of IMF due to the
proximity of massive stars around the cluster.
