Vacuum ultraviolet photoabsorption spectroscopy of space-related ices
- 1School of Electronic Engineering and Computer Science, Queen Mary University of London, London E1 4NS, UK
- 2INAF - Osservatorio Astronomico di Roma, Monte Porzio Catone RM-00078, Italy
- 3Astronomical Institute of Slovak Academy of Sciences, 059 60 Tatranská Lomnica, Slovakia
- 4School of Physical Sciences, The Open University, Milton Keynes MK7 6AA, UK
- 5ISA, Department of Physics and Astronomy, Aarhus University, Aarhus 8000, Denmark
- 6School of Physical Sciences, University of Kent, Canterbury CT2 7NH, UK
- 7INAF – Osservatorio Astrofisico di Catania, Catania 95123, Italy
- 8Institute of Space Astrophysics and Planetology, IAPS-INAF, Rome 00133, Italy
- 9Instituto de Astronomía y Ciencias Planetarias, INCT, Universidad de Atacama, Copiapó, Chile
Ices are widely present in the cold regions across the Universe, for instance, in the interstellar medium as mantles on interstellar and circumstellar dust and on the surfaces of small bodies of the Solar System - beyond the distance around 3-5 AU known as the “snowline" (i.e. at temperatures below 150-170 K). The continuous energetic processing of icy objects in the Solar System induces physical and chemical changes within the ice. Laboratory experiments that simulate energetic processing (ions, photons, and electrons) of ices are therefore essential for interpreting and directing future astronomical observations.
Here we provide vacuum ultraviolet (VUV) and UV-Vis photoabsorption spectroscopic data of pristine and energetically processed (electron irradiated) space-related ices. Experiments were performed using a custom-made Portable Astrochemistry Chamber (PAC), which has a base pressure of 10-9 mbar. Photoabsorption spectra of ices were measured at the AU-UV beam line of the ASTRID2 synchrotron light source at Aarhus University in Denmark (see Eden et al. 2006; Palmer et al. 2015). We present the results of three series of experiments: one dedicated to the study of nitrogen- and oxygen-rich ices (Ioppolo et al., 2020); the other one to the spectroscopic study of carbonic acid as formed and destroyed under conditions relevant to space (Ioppolo et al., 2021); and the third one to the study of photoabsorption spectra of O2 ice, both pure and mixed with other species (Migliorini et al, 2021).
Results are discussed in light of their relevance to various astrophysical environments, e.g., the icy moons of Saturn and Jupiter. Laboratory VUV-UV-vis spectra of ices can help their future identification on the surface of icy objects in the Solar System by the upcoming Jupiter ICy moons Explorer mission and on interstellar dust by the James Webb Space Telescope spacecraft.
This research was partly supported by the Italian Space Agency (Grant ASI-INAF n. 2018-25-HH-0).
REFERENCES:
Eden, S., Limão-Vieira, P., Hoffmann, S. V., & Mason, N. J. 2006, Chem. Phys., 323, 313
Ioppolo, S., Kanuchova Z., James, R.L., Dawes, A., Jones, N.C., Hoffmann, S.V., Mason, N.J., Strazzulla, G. 2020, Astron. Astrophys. 641, A154
Ioppolo, S., Kanuchova Z., James, R.L., Dawes, A., Ryabov, A., Dezalay, J., Jones, N.C., Hoffmann, S.V., Mason, N.J., Strazzulla, G. 2021, Astron. Astrophys. 645, A172
Migliorini, A., Kanuchova Z., Ioppolo, S., Jones, N.C., Hoffmann, S.V., Tosi, F., Piccioni, G., Barbieri, M. 2021, Icarus, submitted
Palmer, M. H., Ridley, T., Hoffmann, S. V., et al. 2015, J. Chem. Phys., 142, 134302
How to cite: Ioppolo, S., Kanuchova, Z., James, R. L., Dawes, A., Ryabov, A., Dezalay, J., Jones, N. C., Hoffmann, S. V., Mason, N. J., Strazzulla, G., Migliorini, A., Tosi, F., Piccioni, G., and Barbieri, M.: Vacuum ultraviolet photoabsorption spectroscopy of space-related ices, European Planetary Science Congress 2021, online, 13–24 Sep 2021, EPSC2021-580, https://doi.org/10.5194/epsc2021-580, 2021.
