  Possible forsterite nanoparticle model of the Extended Red Emission(ERE) is
proposed on the basis of photo-luminescence of forsterite after gamma-ray and
neutron irradiation. Forsterite exhibits interesting thermoluminescence
spectrum similar to ERE of Red Rectangle after irradiation in low temperature.
It is shown that the forsterite after thermoluminescence is over exhibits
photo-luminescence(PL) when Ultraviolet ray is irradiated. The structure of PL
spectrum is almost similar to that of thermoluminescence. In order to explain
small variations of the peak position of wavelength of ERE spectrum, possible
nanoparticle model of forsterite is investigated. Our model is consistent to
the ISO observation data in near and middle infrared region, which suggest the
existence of forsterite.
