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 \mu m. We observe the aromatic emission features ( AEFs ) at 6.2 , 7.7 , 8.6 , 11.3 , and 12.7 \mu m , 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 \mu m. 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 ) .