Near-IR fluorescent molecular hydrogen emission from NGC 2023

Abstract

Spectra from 1 to 2.5 micron, 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 hydrogen 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 45,000 K above the ground state. These data may be used to constrain models both of photodissociation regions and of fluorescent excitation for molecular hydrogen.