1. Infrared complex refractive index of N-containing astrophysical ices free of water processed by cosmic-ray simulated in laboratory.
- Author
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Rocha, W.R.M., Pilling, S., Domaracka, A., Rothard, H., and Boduch, P.
- Subjects
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REFRACTIVE index , *COSMIC rays , *ALBEDO , *IONIZING radiation , *INFRARED absorption , *RADIATIVE transfer , *SOLAR system - Abstract
Several nitrogen-containing molecules have been unambiguously identified in the Solar System and in the Interstellar Medium. It is believed that such a rich inventory of species is a result of the energetic processing of astrophysical ices during the interaction with ionizing radiation. An intrinsic parameter of matter, the complex refractive index, stores all the "chemical memory" triggered by energetic processing, and therefore might be used to probe ice observations in the infrared. In this study, four N-containing ices have been condensed in an ultra-high vacuum chamber and processed by heavy ions (O and Ni) with energies between 0.2 and 15.7 MeV at the Grand Accélérateur National d'Ions Lourds (GANIL), in Caen, France. All chemical changes were monitored in situ by Infrared Absorption Spectroscopy. The complex refractive index was calculated directly from the absorbance spectrum, by using the Lambert-Beer and Kramers-Kroning relations, and the values are available in an online database: https://www..univap.br/gaa/nkabs-database/data.htm. As a result, other than the database, it was observed that non-polar ices are more destroyed by sputtering than polar ones. Such destruction and chemical evolution lead to variation in the IR albedo of samples addressed in this paper. Unlabelled Image • Complex refractive index is key parameter in radiative transfer models of dusty media. • The dataset provided in this paper reduces the lack of data for the astrochemical community. • In general, the refractive index modification triggered by cosmic-ray bombardment, leads to an albedo decreasing in the infrared. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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