Description
We present laboratory measurements of the wavelength-dependent dust opacity for amorphous Mg/Fe-silicate particles in the far-infrared range. Such amorphous silicates represent likely the major dust component in interstellar space. Their opacity bears a strong temperature dependence, which is not yet fully explored. We have synthesized silicates with a variable Mg/Fe ratio and have measured their absorption spectra in a wavelength range between 50 micrometers and 4 millimeters at temperatures down to 10 K. We find additionally a systematic dependence of the opacity on the iron content, which is probably related to the incorporation of iron ions as both network formers and network modifiers.
Author
Pierre Mohr
(Astrophysikalisches Institut und Universitäts-Sternwarte Jena)