2021年4月27日
Formation of chiral CO polyhedral crystals on icy interstellar grains
Monthly Notices of the Royal Astronomical Society
- 巻
- 505
- 号
- 1
- 開始ページ
- 1530
- 終了ページ
- 1542
- 記述言語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1093/mnras/stab1173
- 出版者・発行元
- Oxford University Press (OUP)
<title>Abstract</title>
The crystallinity and morphology of solid CO on icy interstellar grains were examined by observing the deposition, crystallisation, and UV and electrons irradiation of solid CO using transmission electron microscopy. Herein, we found that solid CO deposited in molecular clouds was crystalline, and that even if amorphous CO was deposited amorphous CO crystallised within 103 years at 10 K. Conversely, crystalline CO was not amorphised by UV rays or electron beam at 10 K. These results indicated the occurrence of chiral crystalline CO instead of amorphous CO in space. Furthermore, the large surface diffusion coefficients of CO on amorphous H2O and crystalline CO at 10 K facilitated the morphological equilibration of crystalline CO. Bad wetting of crystalline CO with amorphous H2O proved that the morphology of the ice grains was not spherical with an onion-like structure, as hitherto assumed, but rather it was a polyhedral crystalline CO attached to amorphous H2O. This has important implications for phenomena associated with the collision and subsequent sticking between ice grains, surface chemical reactions, non-thermal desorption of molecules and the origin of homochirality in interstellar biomolecules.
The crystallinity and morphology of solid CO on icy interstellar grains were examined by observing the deposition, crystallisation, and UV and electrons irradiation of solid CO using transmission electron microscopy. Herein, we found that solid CO deposited in molecular clouds was crystalline, and that even if amorphous CO was deposited amorphous CO crystallised within 103 years at 10 K. Conversely, crystalline CO was not amorphised by UV rays or electron beam at 10 K. These results indicated the occurrence of chiral crystalline CO instead of amorphous CO in space. Furthermore, the large surface diffusion coefficients of CO on amorphous H2O and crystalline CO at 10 K facilitated the morphological equilibration of crystalline CO. Bad wetting of crystalline CO with amorphous H2O proved that the morphology of the ice grains was not spherical with an onion-like structure, as hitherto assumed, but rather it was a polyhedral crystalline CO attached to amorphous H2O. This has important implications for phenomena associated with the collision and subsequent sticking between ice grains, surface chemical reactions, non-thermal desorption of molecules and the origin of homochirality in interstellar biomolecules.
- リンク情報
- ID情報
-
- DOI : 10.1093/mnras/stab1173
- ISSN : 0035-8711
- eISSN : 1365-2966