星間ガス相における水分子形成の低温反応速度定数の測定
Water molecule formation in the diffuse interstellar medium (ISM) proceeds through sequential reactions involving molecular ions such as OH, HO, and HO together with molecular hydrogen. These reaction networks also underpin the synthesis of more complex molecular species in space. Rate coefficients for two critical steps in this pathway were experimentally determined at temperatures below 100 K (spanning 10–100 K). The measured values were substantially larger than those currently adopted in standard astronomical models. Theoretical calculations employing a ring-polymer molecular dynamics framework, which provides a first-principles description of low-temperature barrierless reactions, showed strong agreement with the experimental data. These findings suggest that existing astrochemical models may require revision of the rate parameters used for interstellar water chemistry.
Ring-polymer molecular dynamics calculations provided a first-principles treatment of barrierless gas-phase reactions, yielding rate coefficients at 10–100 K that substantially exceed values used in prior astrochemical models.
The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).
See also:
https://h2-papers.org/en/papers/29942857