We present a multiwavelength study of the formation of massive stellar clusters , their emergence from cocoons of gas and dust , and their feedback on surrounding matter .
Using data that span from radio to optical wavelengths , including Spitzer and Hubble ACS observations , we examine the population of young star clusters in the central starburst region of the irregular Wolf-Rayet galaxy IC 4662 .
We model the radio-to-IR spectral energy distributions of embedded clusters to determine the properties of their HII regions and dust cocoons ( sizes , masses , densities , temperatures ) , and use near-IR and optical data with mid-IR spectroscopy to constrain the properties of the embedded clusters themselves ( mass , age , extinction , excitation , abundance ) .
The two massive star-formation regions in IC 4662 are excited by stellar populations with ages of \sim 4 Ma and masses of \sim 3 \times 10 ^ { 5 } M _ { \odot } ( assuming a Kroupa IMF ) .
They have high excitation and sub-solar abundances , and they may actually be comprised of several massive clusters rather than the single monolithic massive compact objects known as Super Star Clusters ( SSCs ) .
Mid-IR spectra reveal that these clusters have very high extinctions , A _ { V } \sim 20 - 25 mag , and that the dust in IC 4662 is well-mixed with the emitting gas , not in a foreground screen .