Near-IR Fluorescent Molecular Hydrogen Emission from NGC 2023

Michael G. Burton
J.E. Howe
T.R. Geballe
P.W.J.L. Brand

School of Physics, University of New South Wales, Sydney, NSW 2052, Australia
M.Burton@unsw.edu.au
Five College Radio Astronomy Observatory, Department of Physics and Astronomy,
University of Massachusetts, Amherst, MA 01003, USA
jhowe@lyra.phast.umass.edu
Joint Astronomy Centre, 660 N. A'ohoku Place, Hilo, HI 96720, USA
tom@jach.hawaii.edu
Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh, EH9 3HJ, UK
pwb@roe.ac.uk

Abstract:

Spectra from 1 to 2.5m, at 230-430 spectral resolution, are presented of the fluorescent molecular hydrogen line emission from two locations in the reflection nebula NGC 2023. Over 100 H lines can be identified in the spectra, though blending and poor atmospheric transmission mean that reliable level column densities can only be obtained from 35 lines. These latter group include lines from v=1-8 and v=10, spanning an energy range from 6,000 to 45,000K above the ground state. These data may be used to constrain models both of photodissociation regions and of fluorescent excitation for molecular hydrogen.

Keywords: Molecular Processes -- ISM: molecules -- Reflection Nebulae
ISM: individual sources (NGC 2023).

© Copyright Astronomical Society of Australia 1997