对天体生物学具有重要意义的分子的低温合成：宇宙尘埃类似物的催化作用。

Cryogenic synthesis of molecules of astrobiological interest: catalytic role of cosmic dust analogues.

作者信息

Brucato J R, Strazzulla G, Baratta G A, Rotundi A, Colangeli L

机构信息

INAF-Astronomical Observatory of Capodimonte, via Moiariello 16, 80131 Naples, Italy.

出版信息

Orig Life Evol Biosph. 2006 Dec;36(5-6):451-7. doi: 10.1007/s11084-006-9050-5.

DOI:10.1007/s11084-006-9050-5

PMID:17120116

Abstract

We have studied the effects of the substrate, namely amorphous olivine (MgFeSiO(4)) cosmic dust analogues (CDAs), in synthesis of molecules obtained after 200 keV proton irradiation of formamide (NH(2)COH). Formamide has been deposited on the olivine substrate at 20 K. The abundances of new molecular species formed after an irradiation dose of 12 eV/16 amu in formamide pure (i.e. deposited on an inert silicon substrate) and deposited on CDAs have been compared. Specifically, MgFeSiO(4) amorphous olivine is a selective catalyst preventing formation of NH(3) and CN(-) molecules and changing the relative abundances of NH4(+)OCN(-), CO(2), HNCO, CO. We have shown that the role of CDAs has to be taken into account in experiments simulating processes occurring in astronomical environments.

摘要

我们研究了基质，即非晶态橄榄石（MgFeSiO₄）宇宙尘埃类似物（CDAs），在200 keV质子辐照甲酰胺（NH₂COH）后所获得分子的合成过程中的作用。甲酰胺已在20 K的温度下沉积在橄榄石基质上。我们比较了在甲酰胺纯品（即沉积在惰性硅基质上）以及沉积在CDAs上，辐照剂量达到12 eV/16 amu后形成的新分子物种的丰度。具体而言，MgFeSiO₄非晶态橄榄石是一种选择性催化剂，可阻止NH₃和CN⁻分子的形成，并改变NH₄⁺OCN⁻、CO₂、HNCO、CO的相对丰度。我们已经表明，在模拟天文环境中发生的过程的实验中，必须考虑CDAs的作用。