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タイトル
  • en Experimental and Computational Studies on the Physicochemical Behavior of Phosphine Induced by Reactions with H and D Atoms on Interstellar Ice Grains
作成者
アクセス権 metadata only access
主題
  • NDC 420
内容注記
  • Abstract en Phosphine (PH3) is an important molecule in the chemistry of phosphorus (P)-bearing species in the interstellar medium. Interstellar PH3 is thought to primarily form on icy grains, where several surface processes may occur during and after its formation. To better understand the physicochemical behavior of PH3 on icy grains in dense molecular clouds, we performed experimental and computational studies on the reactions of phosphine with H and D atoms at low temperatures. We found that phosphine and its deuterated isotopologue PD3 are released into the gas phase from icy surfaces (porous amorphous, compact amorphous, and crystalline ice) via chemical desorption. Even though the effective desorption cross section did not vary between the different icy surfaces, the desorption fraction was smallest for porous amorphous ice. We confirmed that, at 10 K on icy surfaces, H-D substitution reactions of PH3 and D-H substitution reactions of PD3 occurred following reactions with D and H atoms, respectively. Because the activation barrier for the abstraction of H or D atoms from phosphine is similar to 1500 K, quantum tunneling should play a role at low temperatures. Under the present experimental conditions, the H-D substitution reaction of PH3 was slightly slower than the D-H substitution reaction of PD3. Therefore, the rates of the H-D and D-H substitution reactions should not be constrained by tunneling reactions but rather by other elementary processes such as atom diffusion on ice. Our experimental results suggest the possible presence of a deuterated phosphine isotopologue (PH2D) in PH3-rich interstellar environments.
出版者 en IOP Publishing
日付
    Issued2021-09-09
言語
  • eng
資源タイプ journal article
出版タイプ NA
資源識別子 HDL http://hdl.handle.net/2115/86717
関連
  • isIdenticalTo DOI https://doi.org/10.3847/1538-4357/ac0cf4
収録誌情報
    • PISSN 0004-637X
      • en Astrophysical journal
      • 巻918 号2 開始ページ73
コンテンツ更新日時 2023-07-26