Protostars and Planets VI, Heidelberg, July 15-20, 2013
Herschel far-infrared observations of the Carina Nebula complex - The embedded young stellar and protostellar population
Gaczkowski, Benjamin (University Observatory Munich)
Preibisch, Thomas (University Observatory Munich)
Ratzka, Thorsten (University Observatory Munich)
Roccatagliata, Veronica (University Observatory Munich)
Ohlendorf, Henrike (University Observatory Munich)
Pekruhl, Stephanie (University Observatory Munich)
At a distance of 2.3 kpc, the Carina Nebula is the nearest southern region with a large enough massive stellar population to sample the top of the IMF and displays all phenomena of massive star formation.
We have performed a 9 square-degree Herschel far-infrared survey of the Carina Nebula complex (CNC) which revealed, for the first time, the very complex and filamentary small-scale structure of the dense clouds.
We discovered 642 objects that are independently detected as point-like sources in at least two of the five Herschel bands. About 75% of these are Class 0 protostars with masses between about one and ten solar masses estimated from radiative transfer modeling. Taking the observational limits into account and extrapolating the observed number of Herschel-detected protostars over the stellar initial mass function suggests that the star formation rate of the CNC is about 0.017 solar masses per year.
The spatial distribution of the Herschel young stellar objects (YSO) candidates is highly inhomogeneous and does not follow the distribution of cloud mass. Rather, most Herschel YSO candidates are found at the irradiated edges of clouds and pillars. The currently ongoing star formation process forms only low-mass and intermediate-mass stars, but no massive stars. The characteristic spatial configuration of the YSOs provides support to the picture that the formation of this latest stellar generation is triggered by the advancing ionization fronts.
Around the bubble-shaped HII region Gum 31 (containing the young stellar cluster NGC 3324) in the north-western part of the CNC we identified 752 candidate YSOs from Spitzer, WISE, and Herschel data and analyzed their spectral energy distributions. Their location in the rim of the bubble is suggestive of their being triggered by a ‘collect and collapse’ scenario, which agrees well with the observed parameters of the region which we obtained from density and temperature maps from our Herschel data.
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