宇宙の受精？ 分子雲への生物学的に関連のある宇宙線のインプラント

This study investigates the implantation of astrobiologically relevant elements (e.g., carbon (C), oxygen (O), nitrogen (N), sulfur (S) and phosphorus (P)) into molecular clouds induced by cosmic rays. Using the Monte Carlo toolkit Geant4, we simulated the interaction of incoming high-energy protons and alpha particles with a molecular clump characterized by a centrally concentrated density profile and a mass of approximately 30 M_⊙. The results reveal a spatial gradient in implantation rates, with the highest rates occurring in the central regions due to increased target densities and reduced projectile energy. Protons (p) dominate the implantation process across all regions, followed by O, C, N, S, and P, with element-specific implantation efficiencies varying with distance from the clump center. This research identified regions inside the molecular cloud with distinct domains of atomic implantation enrichment with implications for astrobiology. The region at ∼1 AU exhibits the interesting atom implantation enrichment of the studied atoms, making it particularly significant for the formation of complex organic molecules. The findings highlight the importance of cosmic ray interactions in selectively enriching specific regions of molecular clouds with astrobiologically essential elements.