Terahertz Absorption Spectra of Silicate Cosmic Analog Dusts Using a Novel Spectrometer

Metal containing amorphous silicate grains are expected to be a major component of interstellar dust. Amorphous silicate grains containing magnesium, iron, and calcium have been synthesized in the IWU chemistry department. Our group has completed the construction of an apparatus for obtaining terahertz absorption spectra of cold samples at astronomically interesting temperatures. To study the dusts, we installed dust samples, embedded in low-density polyethylene pellets, in a sample-exchanger and cooled them down to 3.0 Kelvin. Using a blackbody radiation source, a Fourier Transform Spectrometer, and a sensitive millimeter wavelength light detector, we measured the terahertz absorption spectra of several cosmic analog dusts. We present the full analysis of the data here, along with the specific trends observed