VLT-ISAAC 3-5 μm spectroscopy as a new tool for investigating H emission in protostellar jets
Osservatorio Astronomico di Roma, via Frascati 33, 00040 Monte Porzio, Italy e-mail: bruni, vitali, email@example.com
Corresponding author: T. Giannini, firstname.lastname@example.org
Accepted: 26 September 2001
We report 3-5 μm IR spectroscopy obtained with VLT-ISAAC on the IRS17 molecular hydrogen jet in the Vela-D Molecular Cloud. Together with H2 emission lines from the 1 rovibrational state, the spectra show several pure rotational lines of the fundamental state with excitation temperature up to ~22 000 K. We show how theoretical rotation diagrams indicate these lines as unique both to probe the presence of collisionally excited gas in NLTE conditions and to infer the gas density.
Key words: stars: formation / infrared: ISM / ISM: jets and outflows / ISM: individual objects: Vela clouds
© ESO, 2001