J/A+A/655/A74 Sulfur ion irradiation experiments (Ruf+, 2021)
Sulfur ion irradiation experiments to simulate the space weathering of
Solar System body surfaces. Organosulfur compound formation.
Ruf A., Bouquet A., Schmitt-Kopplin P., Boduch P., Mousis O., Danger G.
<Astron. Astrophys. 655, A74 (2021)>
=2021A&A...655A..74R 2021A&A...655A..74R (SIMBAD/NED BibCode)
ADC_Keywords: Atomic physics
Keywords: solid state: refractory - minor planets, asteroids -
comets: general - methods: laboratory: moleculer - astrochemistry -
astrobiology
Abstract:
Sulfur (S) is of high interest in context of (astro)chemical evolution
and habitability. However, the origin of S-bearing organic compounds
in the Solar System is still not well-constrained.
We tested by laboratory experiments whether complex organosulfur
compounds can be formed when surfaces of icy Solar System bodies are
submitted to high-energy S ions. Methods. Non-S-bearing organic
residues, formed during the processing of astrophysical H2O:CH3
OH:NH3-bearing ice analogs, were irradiated with 105 keV-S 7+ ions
at 10K and analyzed by high-resolving FT-ICR-MS. Resulting data were
comprehensively analyzed, including the tools of network analysis.
Out of many thousand detected compounds, 16% contain at least one
sulfur atom (organosulfur (CHNOS) compounds), as verified via isotopic
fine structures. These residue-related organosulfur compounds are
different to the ones formed during S ion irradiation of ices at 10K.
Furthermore, insoluble, apolar material was formed during the sulfur
irradiation of residues. Potential organosulfur precursors (CHNO
molecules) were identified by means of chemical network analysis.
The finding of organosulfur compounds formed by sulfur irradiation of
organic residues sheds new light into the rich and complex pristine
organosulfur chemistry in the Solar System, as discussed here in
context of current and future space missions. These results indicate
that space weathering of Solar System bodies may lead to the formation
of organosulfur compounds.
Description:
An organic residue was first formed by Ar7+ -irradiated ices (at
105keV), composed of H2O:CH3OH:NH3 (2:1:1) at 15K. The processed
ice was warmed up to 300K and the resulting organic residue was then
irradiated with S7+ ions (at 105keV) at 10K again. The resulting
sample was probed for the presence of organosulfur species, and
compared to the Ar7+ -irradiated ice sample.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablec1.dat 60 908 List of 908 CHNOS molecular formulas present in
the S 7+ -over-irradiated residue
tablec2.dat 52 29 List of 29 potential direct CHNOS precursors
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Byte-by-byte Description of file: tablec1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Id [1/908] Identification number
5- 13 F9.5 --- m/z Experimental signal m/z (in atomic mass units)
14- 23 I10 --- Int Intensity, in arbitrary units
25- 30 F6.3 ppm e_Int [] Error of intensity
33- 46 A14 --- Ion Ion formula
49- 52 F4.2 --- O/C O/C ratio
57- 60 F4.2 --- H/C H/C ratio
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Byte-by-byte Description of file: tablec2.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Id Identification name (DP1-DP29)
6- 15 F10.6 --- m/z Theoretical signal m/z (in atomic mass units)
17- 25 I9 --- Int Intensity, in arbitrary units
27- 38 A12 --- Ion Ion formula
41- 44 F4.2 --- O/C O/C ratio
49- 52 F4.2 --- H/C H/C ratio
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Acknowledgements:
Alexander Ruf, rufalexan(at)gmail.com
(End) Patricia Vannier [CDS] 09-Sep-2021