Forsterite formation constrained by infrared spectra of dust aggregates

Abstract

A coma of a long-period comet often exhibits infrared spectral features of forsterite, while comet formation took place in the outer solar nebula where the temperature is too low for amorphous silicates to crystallize. The origin of forsterite provides a clue to better understand the environment of the comet formation region and thus a link between comets and planetesimals. Here we explore the origin of forsterite in cometary dust by comparing the observed forsteritic features with the calculated absorption cross sections for our model dust aggregates.