SIMBAD references

2007A&A...474..941G - Astronomy and Astrophysics, volume 474, 941-950 (2007/11-2)

Quantitative optical and near-infrared spectroscopy of H2 towards HH 91A.


Abstract (from CDS):

Optical and near-infrared spectroscopy of molecular hydrogen in interstellar shocks provide a very powerful probe of the physical conditions that prevail in interstellar shocks. Integral-field spectroscopy of H2 in the optical wavelength region and complementary long-slit near-infrared spectroscopy towards HH91A are used to characterize the ro-vibrational population distribution among H2 levels with excitation energies up to 30000cm–1. The detection of some 200 ro-vibrational lines of molecular hydrogen ranging between 7700Å and 2.3µm is reported. Emission lines which arise from vibrational levels up to v'=8 are detected. The H2 emission arises from thermally excited gas where the bulk of the material is at a temperature of 2750K and where 1% is at 6000K. The total column density of shocked molecular hydrogen is N(H2)=1018cm–2. Non-thermal excitation scenarios such as UV fluorescence do not contribute to the H2 excitation observed towards HH91A. The emission of molecular hydrogen towards HH91A is explained in terms of a slow J-shock that propagates into a low-density medium, that has been swept up by previous episodes of outflows that have occurred in the evolved HH90/91 complex.

Abstract Copyright:

Journal keyword(s): ISM: molecules - ISM: Herbig-Haro objects - ISM: jets and outflows

VizieR on-line data: <Available at CDS (J/A+A/474/941): table1.dat table2.dat table3.dat table4.dat>

Simbad objects: 8

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