Key points are not available for this paper at this time.
We observed the reflection nebula (RN) NGC 7023, with the SH module, and the long-slit SL and LL modules, of the InfraRed Spectrograph (IRS) on Spitzer. We also present InfraRed Array Camera (IRAC) and Multiband Imaging Photometer for Spitzer (MIPS) images of NGC 7023 at 3.6, 4.5, 8.0, and 24 µm. We observe the aromatic emission features (AEFs) at 6.2, 7.7, 8.6, 11.3, and 12.7 µm, plus a wealth of weaker features. We find new unidentified interstellar emission features at 6.7, 10.1, 15.8, 17.4, and 19.0 µm. Possible identifications include aromatic hydrocarbons or nanoparticles of unknown mineralogy. We see variations in relative feature strengths, central wavelengths, and feature widths, in the AEFs and weaker emission features, depending on both distance from the star and nebular position (SE vs. NW). Subject headings: dust, extinction — infrared: ISM — ISM: individual (NGC 7023) — ISM: lines and bands — ISM: molecules — reflection nebulae 1.
Werner et al. (Wed,) studied this question.