Long-slit spectroscopy of the 3 um PAH emission in the Orion Bar

G.C. Sloan (NASA Ames), C.E. Woodward (Univ. of Wyoming), T.R. Geballe (UKIRT), J.D. Bregman, L.J. Allamandola (NASA Ames)

1995, BAAS, 27, 1314

We have obtained long-slit spectra of the Orion Bar at 3 µm, using CGS4 at UKIRT. The spectra cover the main PAH band at 3.29 µm, the satellite PAH band at 3.4 µm, the underlying plateau extending out to 3.6 µm, and additional weaker features. We wish to follow up on the narrow-band imaging of the Bar by Bregman et al. (1996, this AAS meeting), which suggests that the Bar is very clumpy and contains two distinct PAH populations: primitive PAHs with many aliphatic sidegroups within clumps, and highly processed PAHs in the interclump medium, which have had their sidegroups stripped away. We also compare the distribution of the plateau emission to the main band at 3.29 µm, and study additional suspected emission features.

We presented these preliminary findings at the January, 1996 meeting of the AAS, and we published more complete results a year later (Sloan et al. 1997, ApJ, 474, 735).

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Last modified 27 May, 2008. © Gregory C. Sloan and others.