Oxford University Press;London: Oxford University Press
摘要:
摘要： This paper reports the first measurements of solid-phase vacuum-ultraviolet (VUV) absorption cross-sections of heavy isotopologues present in icy dust grain mantles of dense interstellar clouds and cold circumstellar environments. Pure ices composed of D2O, CD3OD, 13CO2, and 15N15N were deposited at 8 K, a value similar to the coldest dust temperatures in space. The column density of the ice samples was measured in situ by infrared spectroscopy in transmittance. VUV spectra of the ice samples were collected in the 120-160 nm (10.33-7.74 eV) range using a commercial microwave discharged hydrogen flow lamp as the VUV source. Prior to this work, we have recently submitted a similar study of the light isotopologues (Cruz-Diaz, Muñoz Caro & Chen). The VUV spectra are compared to those of the light isotopologues in the solid phase, and to the gas phase spectra of the same molecules. Our study is expected to improve very significantly the models that estimate the VUV absorption of ice mantles in space, which have often used the available gas phase data as an approximation of the absorption cross sections of the molecular ice components. We will show that this work has also important implications for the estimation of the photodesorption rates per absorbed photon in the ice. 其他題名： Mon. Not. R. Astron. Soc 出版者： London: Oxford University Press 出版日期： 2014-04-11 出處： Monthly notices of the Royal Astronomical Society, 2014-04, Vol.439 (3), p.2370-2376 資源來源： Alma/SFX Local Collection 版權： 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society 2014 版權： Copyright Oxford University Press, UK Apr 11, 2014 識別號： ISSN: 0035-8711 識別號： ISSN: 1365-8711 識別號： ISSN: 1365-2966 識別號： EISSN: 1365-2966 識別號： DOI: 10.1093/mnras/stu084
