Direct measurement of chemical composition of SO$_{x}$ in impact vapor using a laser gun

The SO$_{3}$/SO$_{2}$ ratio of the impact vapor cloud is a key parameter for understanding the environmental perturbation caused by the impact-induced SO$_{x}$ and the killing mechanism of. the mass extinction at the K-Pg boundary. We conducted hypervelocity impact experiments using a high-speed laser gun (GEKKO XII-HIPER, ILE, Osaka University) and measured the chemical compositions of the SO$_{x}$ released from CaSO$_{4}$. The experimental result indicates that SO$_{x}$ are dominated by SO$_{3}$. It implies that the SO$_{x}$ generated by the K-Pg impact would have been also dominated by SO$_{3}$, because the SO$_{3}$/SO$_{2}$ ratio of natural planetary scale impact vapor clouds would have been larger than that of the experimental result of this study.