Instantaneous formation of interstellar minerals and mineral quantum dots†

Abstract

Our understanding of the formation pathways of interstellar mineral dust is still evolving. This study investigated the formation of astrophysical mineral dust, such as olivine, by shock processing. Low-velocity (∼1.8 km s⁻¹) interstellar shock conditions were simulated using high-intensity shock tubes. These conditions enabled the examination of various cosmic mineral dust precursors such as the mixtures of Mg, Fe and SiO₂ under a shock strength of approximately 5.6 M and temperatures around 7300 K. Analysis of the processed samples revealed the presence of Mg-rich olivine, forsterite, MgO quantum dots (QD), and magnetite. These results indicate that shockwaves can rapidly induce dust formation in interstellar space. Furthermore, we demonstrated that shock processing of mineral dust precursors could contribute to the formation of crystalline silicate dust observed in comets and the creation of chondrules, which are observed in chondritic meteorites.