Astronomy and Astrophysics, volume 540A, 81-81 (2012/4-1)
Jet-driving protostars identified from infrared observations of the Carina Nebula complex.
OHLENDORF H., PREIBISCH T., GACZKOWSKI B., RATZKA T., GRELLMANN R. and McLEOD A.F.
Abstract (from CDS):
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. We used archive data to construct large (>2°x2°) Spitzer IRAC mosaics of the Carina Nebula and performed a spatially complete search for objects with excesses in the 4.5µm 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. The radiative-transfer modelling suggests that the jet sources are protostars with masses between ∼1M☉ and ∼10M☉ that are surrounded by circumstellar disks and embedded in circumstellar envelopes. The estimated protostar masses ≤10M☉ 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.