Vacuum ultraviolet photodesorption of hydrogen sulfide

Yen-Yu Hsu^1*, Chun-Chi Huang¹, Yu-Jung Chen¹

¹Department of Physics, National Central University, Taoyuan, Taiwan

* Presenter:Yen-Yu Hsu, email:s108202518@g.ncu.edu.tw

Hydrogen sulfide (H2S), the most abundant sulfide-bearing species in the interstellar medium (ISM), can be seen as a precursor of biochemical molecules. According to the literatures, H2Sx (x>1) and S-chain (Sx) molecules have been confirmed as the main photoproducts. However, the photodesorption of H2S ices hasn’t been studied in detail. In this work, we examined the structural effect on the photodesoroption of H2S ices deposited at different temperatures. The results show that the photodesorption yield of ices deposited at 70 K (crystalline phase) is less than those deposited at 13 K (amorphous phase). Besides, although the smaller photodepletion is measured in the cases of depositing at 70 K, each VUV irradiation pathway almost has the same proportion whether in 13 K or 70 K. We obtained the proportion of H2S desorption, H2S2 production, and Sx production is about 10%, 30%, and 60%, respectively.

Keywords: Hydrogen sulfide, VUV, Photodesorption