On the Abiotic Origin of Dimethyl Sulfide: Discovery of Dimethyl Sulfide in the Interstellar Medium

The Astrophysical Journal Letters, Journal Year: 2025, Volume and Issue: 980(2), P. L37 - L37

Published: Feb. 18, 2025

Abstract Following the discovery of dimethyl sulfide (DMS; CH 3 SCH ) signatures in comet 67P/Churyumov–Gerasimenko, we report first detection this organosulfur species interstellar medium during exploration an ultradeep molecular line survey performed toward Galactic center cloud G+0.693-0.027 with Yebes 40 m and IRAM 30 telescopes. We derive a column density N = (2.6 ± 0.3) × 10 13 cm −2 , yielding fractional abundance relative to H 2 ∼1.9 −10 . This implies that DMS is factor ∼1.6 times less abundant than its structural isomer SH ∼30 O-analog ether (CH OCH cloud, excellent agreement previous results on various O/S pairs. Furthermore, find remarkable resemblance between DMS/CH OH (∼1.7 −3 (∼1.3 ). Although chemistry beyond Earth has yet be fully disclosed, provides conclusive observational evidence efficient abiotic production medium, casting doubt using as reliable biomarker exoplanet science.

Language: Английский

---

A JWST/DiSCo-TNOs portrait of the primordial Solar System through its trans-Neptunian objects

Nature Astronomy, Journal Year: 2024, Volume and Issue: 9(2), P. 230 - 244

Published: Dec. 19, 2024

Language: Английский

---

Laboratory infrared spectra and fragmentation chemistry of sulfur allotropes

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: July 15, 2024

Sulfur is one of six life-essential elements, but its path from interstellar clouds to planets and their atmospheres not well known. Astronomical observations in dense have so far been able trace only 1 percent cosmic sulfur, the form gas phase molecules volatile ices, with missing sulfur expected be locked a currently unidentified form. The high abundances inferred icy rocky solar system bodies indicate that an efficient pathway must exist atomic diffuse medium some refractory sulfur. One hypothesis formation allotropes, particularly stable S

Language: Английский

---

Evidence for Abiotic Dimethyl Sulfide in Cometary Matter

The Astrophysical Journal, Journal Year: 2024, Volume and Issue: 976(1), P. 74 - 74

Published: Nov. 1, 2024

Technological progress related to astronomical observatories such as the recently launched James Webb Space Telescope (JWST) allows searching for signs of life beyond our Solar System, namely in form unambiguous biosignature gases exoplanetary atmospheres. The tentative assignment a $1-2.4\sigma$ spectral feature observed with JWST atmosphere exoplanet K2-18b gas dimethyl sulfide (DMS; sum formula C$_2$H$_6$S) raised hopes that, although controversial, second genesis had been found. Terrestrial atmospheric DMS is exclusively stemming from marine biological activity and no natural abiotic source has identified - neither on Earth nor space. Therefore, considered robust biosignature. Since comets possess pristine inventory complex organic molecules origin, we have searched high-resolution mass spectra collected at comet 67P/Churyumov-Gerasimenko, target European Agency's Rosetta mission, signatures DMS. Previous work reported presence C2H6S signal when was near its equinox but distinction structural isomer ethanethiol remained elusive. Here reassess these evaluate additional data. Based differences electron ionization induced fragmentation pattern two isomers, show that significantly better compatible observations. Deviations between expected intensities are $<1\sigma$, while they $2-4\sigma$. local abundance relative methanol deduced data (0.13$\pm$0.04)%. Our results provide first evidence existence an synthetic pathway cometary matter hence motivate more detailed studies sulfur chemistry analogs. [...]

Language: Английский

---

Abiotic formation of alkylsulfonic acids in interstellar analog ices and implications for their detection on Ryugu

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: May 23, 2024

For the last century, source of sulfur in Earth's very first organisms has remained a fundamental, unsolved enigma. While sulfates and their organic derivatives with S(+VI) oxidation state represent core nutrients contemporary biochemistry, limited bioavailability during early Archean period proposed that more soluble S(+IV) compounds served as initial for terrestrial microorganisms. Here, we reveal via laboratory simulation experiments three simplest alkylsulfonic acids-water compounds-can be efficiently produced interstellar, sulfur-doped ices through interaction galactic cosmic rays. This discovery opens previously elusive path into synthesis vital astrobiological significance untangles fundamental mechanisms facile preparation sulfur-containing, biorelevant organics extraterrestrial ices; these molecules can eventually incorporated comets asteroids before delivery detection on Earth such Murchison, Tagish Lake, Allende meteorites along carbonaceous asteroid Ryugu.

Language: Английский

---

Formation and desorption of sulfur chains (H2Sx and Sx) in cometary ice: Effects of ice composition and temperature

Monthly Notices of the Royal Astronomical Society, Journal Year: 2024, Volume and Issue: 533(1), P. 967 - 978

Published: July 22, 2024

ABSTRACT The reservoir of sulphur accounting for depletion in the gas dense clouds and circumstellar regions is still unclear. One possibility formation chains, which would be difficult to detect by spectroscopic techniques. This work explores chains experimentally, both pure H$_2$S ice samples H$_2$O:H$_2$S mixtures. An ultrahigh vacuum chamber, ISAC, eqquipped with FTIR QMS, was used experiments. Our results show that H$_2$S$_x$ species efficient, not only samples, but also water-rich samples. Large are formed more efficiently at low temperatures ($\approx$10 K), while high ($\approx$50 K) favour short chains. Mass spectra H$_2$S$_x$, x = 2–6, presented first time. Their analysis suggests favoured comparison S$_x$ Nevertheless, detection several S$_x^+$ fragments H$_2$S:H$_2$O mixtures presence S$_8$ irradiated could sublimate from 260 K. ROSINA instrument data cometary Rosetta mission detected mass-to-charge ratios 96 128. Comparing these detections our experiments, we propose two alternatives: (1) H$_2$S$_4$ H$_2$S$_5$ responsible those S$_3^+$ S$_4^+$ cations, respectively, or (2) species, sublimating being fragmented mass spectrometer. If parent molecule, then S$_5^+$ S$_6^+$ cations future missions broadening spectrometer range.

Language: Английский

---

Hot Sulfur on the Rocks: The Reaction of Electronically Excited Sulfur Atoms with Water in an Ice-Surface Model

ACS Earth and Space Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: March 25, 2025

In this contribution, we present a theoretical investigation of the reaction involving atomic sulfur in its first electronically excited state, 1D, and H2O on an ice-surface model. This study is motivated by work Giustini et al. (ACS Earth Space Chem., 2024, 8, 2318), which indicated strong effect presence four additional water molecules S(1D) + compared to pure gas-phase case. Our simulation treats long-range interactions (H-bonds dispersion forces) with ice much more realistic way being based use cluster 18 molecules, thus overcoming limits small used According our results, reacts via two possible mechanisms: (1) addition O atom molecule formation H2OS or (2) insertion into one O–H bonds HOSH. Both HOSH are stabilized energy dissipation rather than isomerizing dissociating products as seen reaction. The interaction surrounding affects entire pathway stabilizing intermediate species, reducing some barriers, impeding only two-product open channel can be produced UV-induced photodissociation various precursor surface interstellar cometary other high-energy processes induced electrons cosmic rays also bulk. Therefore, results help elucidating mysterious chemistry occurring icy mantles grains nuclei. Furthermore, demonstrates that product branching ratios reactions should not uncritically modeling chemistry.

Language: Английский

---

Sulphur ion implantation into O2, CO, and CO2 ices: Implications for the formation of sulphur-bearing molecules in the Kuiper Belt

Icarus, Journal Year: 2023, Volume and Issue: 411, P. 115926 - 115926

Published: Dec. 19, 2023

Previous experimental work has systematically investigated the radiolytic sulphur chemistry arising as a result of implantation reactive ions into various oxygen-bearing molecular ices (e.g., H2O, CO2) so to better understand surface Galilean moons Jupiter, where are sourced from giant Jovian magnetosphere. However, significantly less attention been paid analogous occurring under conditions relevant Kuiper Belt, supplied by solar wind may implant surfaces icy bodies that rich in volatile such O2, CO, or CO2. This paper presents results study on 290–400 keV S+ pure and CO2 temperature, pressure, radiation dose, ice deposition with particular focus potential synthesis simple inorganic sulphur-bearing molecules SO2, OCS, CS2). Experiments involving were also performed at higher temperatures more typically associated moon system determine whether there exist any differences resulting these two regions Solar System. Our constitute first systematic investigation solid-phase Belt mediated ion component wind, thus represent an important step forward our understanding astrochemical processes outermost depths

Language: Английский

---

Gas-Phase and Model Ice-Surface Reactions of S(¹D) with Water and Methanol: A Computational Investigation and Implications for Cosmochemistry/Astrochemistry

ACS Earth and Space Chemistry, Journal Year: 2024, Volume and Issue: 8(11), P. 2318 - 2333

Published: Nov. 4, 2024

Gas-phase reactions of atomic sulfur in its first electronically excited metastable state, S(1D), with water and methanol have been theoretically investigated to characterize their potential energy surfaces, the reaction mechanisms, product branching fractions. According our results, both proceed formation bound intermediates that, for isolated systems, decompose into products because large content which they are formed. The SO(a 1Δ) + H2 channel is only open one S(1D) H2O reaction, while many channels CH3OH reaction. For latter case, statistical estimates fractions indicate that main those leading CH2OH SH, H2CO H2S, H2CS H2O, CH3 HSO. mechanism related O(1D) CH3SH has also unveiled. Since can be stabilized by loss surrounding species on ice or liquid water, gain some insights possible effects molecules, we analyzed how two behave when four additional molecules added. conclusion initial formed insertion addition mechanism, namely, HOSH (hydrogen thioperoxide) H2OS CH2OHSH (mercaptomethanol), CH4OS CH3OSH (methyl CH3OH, as well CH3SOH sulfenic acid) CH3SH, will probably interaction molecules. Our results help understanding chemistry space, especially case comets. On hand, gas-phase could account SO source necessary explain observed distribution this obtained using Plateau de Bure interferometer Institut Radioastronomie Millimétrique (IRAM) Hale Bopp comet. other S/O-containing identified ROSINA (Rosetta Orbiter Spectrometer Ion Neutral Analysis) during enhanced dust emission events 67/P comet (e.g., gross formula HSO, H2SO, CH4OS) occurring exposed work.

Language: Английский

---

Dual Sources of S₂ Observed in Comet 67P: Insights from Comparing ROSINA Measurements and Laboratory Simulations

The Planetary Science Journal, Journal Year: 2024, Volume and Issue: 5(10), P. 234 - 234

Published: Oct. 1, 2024

Abstract Hydrogen sulfide (H 2 S) is the fifth most abundant molecule observed in coma of comet 67P/Churyumov–Gerasimenko (67P). Prior to its incorporation into cometary materials, H S likely underwent ultraviolet (UV) radiation exposure, which thought initiate a complex sulfur chemistry. We present an investigation UV photochemistry ices using infrared, Raman, and mass spectrometry techniques. Our study reveals production allotropes ranging from 6 , alongside polysulfanes n = 2–3). Temperature-programmed desorption measurements postirradiation exhibit two peaks for molecules: broad peak between 80 140 K distinct at ∼245 K. Notably, larger 3 –S 5 exclusively display 245 peak. Furthermore, ROSINA /H ratio during dust impact events previously reported ratios undisturbed are compared our laboratory-determined values. This analysis identifies sources : volatile potentially sublimated directly comet’s surface secondary source resulting fragmentation chains impacts. determined produced initial both component refractory with conducted irradiation incident fluence 2.25 × 10 17 photons cm −2 . These laboratory-derived concordance measurements. When extrapolated fluences anticipated molecular clouds, this photoprocessing mechanism offers plausible explanation measured 67P.

Language: Английский

---