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Paper: RCW 108: Star formation in a Nearby Troubled Environment
Volume: 440, UP2010: Have Observations Revealed a Variable Upper End of the Initial Mass Function?
Page: 47
Authors: Comerón, F.; Schneider, N.
Abstract: At 1.3 kpc from the Sun, RCW 108 is the region hosting the latest star forming episode of the extended Ara OB1 association. It is also one of the most promising examples where triggered star formation may be going on at present. The trigger is the nearby cluster NGC 6193, which is clearly eroding a molecular cloud producing a bright, rim-shaped HII region. The most prominent star forming site in RCW 108, IRAS 16362-4845, is a compact HII region embedded in the molecular cloud where infrared images reveal a moderately rich cluster. Deep, adaptive-optics-assisted imaging of this cluster shows its weird appearance, characterized by a marked scarcity of faint members and a lack of central concentration of its brightest stars. A detailed analysis of the near-infrared spectral energy distribution of the cluster members confirms that the IRAS 16362-4845 is characterized by a top-heavy stellar mass function, with a very shallow slope that extends all the way from the most massive, late O-type stars of the cluster down to subsolar masses. Given the peculiar environment in which IRAS 16362-4845 resides, it is tempting to relate the unusual features of its embedded stellar population to the injection of energy from the most massive members of the neighboring NGC 6193 cluster into its parental cloud. This supports the view that star formation in heavily disturbed environments can give rise to unusual stellar mass functions dominated by massive stars, and provides a nearby example where the outcome can be observed in remarkable detail.
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