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arXiv · 1202.3636

Jet-driving protostars identified from infrared observations of the Carina Nebula complex

Henrike Ohlendorf·Thomas Preibisch·Benjamin Gaczkowski·Thorsten Ratzka·Rebekka Grellmann·Anna F. McLeod
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Abstract

Aims: Jets are excellent signposts for very young embedded protostars, so we want to identify jet-driving protostars as a tracer of the currently forming generation of stars in the Carina Nebula, which is one of the most massive galactic star-forming regions and which is characterised by particularly high levels of massive-star feedback on the surrounding clouds. Methods: We used archive data to construct large (> 2 deg x 2 deg) Spitzer IRAC mosaics of the Carina Nebula and performed a spatially complete search for objects with excesses in the 4.5 micron band, typical of shock-excited molecular hydrogen emission. We also identified the mid-infrared point sources that are the likely drivers of previously discovered Herbig-Haro jets and molecular hydrogen emission line objects. We combined the Spitzer photometry with our recent Herschel far-infrared data to construct the spectral energy distributions, and used the Robitaille radiative-transfer modelling tool to infer the properties of the objects. Results: The radiative-transfer modelling suggests that the jet sources are protostars with masses between ~1 M_sol and ~10 M_sol that are surrounded by circumstellar disks and embedded in circumstellar envelopes. Conclusions: The estimated protostar masses < 10 M_sol suggest that the current star-formation activity in the Carina Nebula is restricted to low- and intermediate-mass stars. More optical than infrared jets can be observed, indicating that star formation predominantly takes place close to the surfaces of clouds.

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Henrike Ohlendorf, Thomas Preibisch, Benjamin Gaczkowski, Thorsten Ratzka, Rebekka Grellmann, Anna F. McLeod. 2012-02-16. Jet-driving protostars identified from infrared observations of the Carina Nebula complex. https://doi.org/10.1051/0004-6361%2F201118181

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