Two-step excitation of molecular hydrogen

Two-step excitation of molecular hydrogen

2014 A stepwise excitation of H2 is performed. Electron impact populates the metastable c 303A0u state then an optical resonance allows the excitation of 303A3g, 303A0g or 30394g states. We observed the selectivity of the electron impact excitation. The laser light used for the optical resonance was linearly polarized, the alignment produced allowed the observation of the Hanle effect on the 3 ...

Molecular Hydrogen Excitation around Active Galactic Nuclei

We report R ∼ 3000 Very Large Telescope ISAAC K-band spectroscopy of the nuclei (i.e. central 100–300pc) of nine galaxies hosting an active galactic nucleus. For five of these we also present spectra of the circumnuclear region out to 1 kpc. We have measured a number of molecular hydrogen lines in the ν = 1−0, 2−1, and 3−2 vibrational transitions, as well as the Brγ and He i recombination lines...

Molecular Hydrogen Excitation in Gas Clouds

Resonances in the electronic excitation of molecular hydrogen.

Ab initio R-matrix scattering calculations are presented for electron-Hp collisions for energies up to 30 eV. Excitation from the ground state, X 'Xg+, to five accurately represented, low-lying electronic states, b 'Z " +, a 'Zg+, B 'Z,+, c'H " and C 'H " is explicitly considered. An attempt is made to rationalize the wealth of experimental data. Resonance structures similar to those assigned e...

Molecular hydrogen morphology, kinematics and excitation in AFGL2688 and NGC7027

We report the first results of spectro-imaging postAGB objects in the near-infrared K’-band using a new instrument calledBEAR. This instrument has been used to obtain high spatial (0.6′′) and spectral (∼ 40 km s−1) resolution observations of the proto-planetary nebula AFGL 2688 and the young planetary nebula NGC 7027. The current paper is devoted to a detailed study of the morphology, velocity ...