1995A&A...295..165M

We have measured the mass absorption coefficient of various kinds of cosmic carbonaceous analogue grains in the FIR-mm up to 2mm. The samples do not present any relevant feature in this spectral range, but are characterised by two distinct spectral trends: the mainly amorphous grains show a spectral emissivity index, β, close to 1, while for micronic graphite particles β is equal to 2. The emissivity spectral behaviour is discussed in terms of structural properties of the grains. The absorption coefficients obtained in this work represent a set of data useful to interpret a variety of FIR-mm astronomical observations and to better identify the actual properties of carbonaceous cosmic dust.