Processing of formic acid-containing ice by heavy and energetic cosmic ray analogues

作者：Bergantini A^*; Pilling S; Rothard H; Boduch P; Andrade D P P

来源：Monthly Notices of the Royal Astronomical Society, 2014, 437(3): 2720-2727.

DOI：10.1093/mnras/stt2082

• astrochemistry
• molecular data
• methods: laboratory: molecular
• techniques: spectroscopic
• ISM: molecules
• infrared: ISM

Formic acid (HCOOH) has been extensively detected in space environments, including interstellar medium (gas and grains), comets and meteorites. Such environments are often subjected to the action of ionizing agents, which may cause changes in the molecular structure, thus leading to formation of new species. Formic acid is a possible precursor of pre-biotic species, such as Glycine (NH2CH2COOH). This work investigates experimentally the physicochemical effects resulting from interaction of heavy and energetic cosmic ray analogues (46 MeV Ni-58(11 +)) in H2O:HCOOH (1:1) ice, at 15 K, in ultrahigh vacuum regime, using Fourier transform infrared spectrometry in the mid-infrared region (4000-600 cm(-1) or 2.5-12.5 mu m). After the bombardment, the sample was slowly heated to room temperature. The results show the dissociation cross-section for the formic acid of 2.4 x 10(-13) cm(2), and half-life due to galactic cosmic rays of similar to 8 x 10(7) yr. The IR spectra show intense formation of CO and CO2, and small production of more complex species at high fluences.

• 出版日期2014-1
• 单位中国地震局