1999ApJ...520..719S

We have simulated extended red emission (ERE) spectra using a model in which this emission arises as photoluminescence from small carbon particles of mixed sp²/sp³ hybridized bonding characteristics. The emission efficiency from such particles can be highly efficient when their size is such that geminate recombination of photoexcited electron hole pairs is enhanced. The amplitude and emission profile of the ERE emission from the diffuse interstellar medium and nebular sources such as NGC 2327 and NGC 7027 can be reproduced with a range of average particle size and size distribution. These carbon particles are components of the same mixtures that yield an accurate fit to the interstellar 2175 Å extinction peak and suggest that ERE emission, the 2175 Å absorption, and infrared absorption at 3.4 µm may arise from the same carbonaceous components of interstellar matter.