Destruction and formation time scales of PAHs around massive stars

Present observational data indicate a complex morphology of infrared radiation from ionized hydrogen regions around massive stars. This morphology reveals itself as a ring-shaped spatial distribution of the radiation intensity at different wavelengths. Usually, the inner and outer rings at 24 μm are observed, while only the outer ring is observed at wavelengths 8 μm as well as at 100-500 μm. This paper presents an attempt to explain the nature of the intensity distribution at different wavelengths due to the destruction and aromatization of dust particles in the ionized hydrogen regions.