Spectral Emission Features of SiO2 Spheres

Silicate dust particles are part of many astronomical objects such as comets and circumstellar discs. In the spectrum, silicates exhibit a number of characteristic emission features. In this paper, we studied the contribution of quartz (SiO2) particles to these features. Using the Mie theory, calculations were made of the intensity of light scattered by such particles. Two spectral features were found in the spectrum—near 9 μm and near 20.5 μm. The main properties of these features are investigated. It is established, that the 9 μm feature is much narrower than the 20.5 μm; with an increase in the size of the scattering particle from very small values the position of spectral features (both 9 μm and 20.5 μm) shifts toward longer wavelengths; the 9 μm feature cannot be clearly seen with particle sizes greater than 18 μm, while the 20.5 μm feature is apparent even at particle radius 60 μm.