Sulfur Archives

This composite shows a section of the interstellar medium scientists X-rayed for sulfur using the Japan-led XRISM (X-ray Imaging and Spectroscopy Mission). X-ray binary GX 340+0 is the inside the red circle drawn in the center. The composite contains a blend of imagery in X-rays (represented in deep blue), infrared, and light. -- NASA

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Press Release

Astrochemistry: XRISM Satellite Measures Sulfur – An Essential Life Component

by Keith CowingJuly 23, 2025July 23, 2025

An international team of scientists have provided an unprecedented tally of elemental sulfur spread between the stars using data from the Japan-led XRISM (X-ray Imaging and Spectroscopy Mission) spacecraft.

X-ray Imaging Spectroscopy Mission (XRISM)

Astrochemistry, Astrogeology, Astronomy & Telescopes, Biosignatures & Paleobiology, Imaging & Spectroscopy, Status Report

XRISM Insights For Interstellar Sulfur

by Keith CowingJune 13, 2025June 12, 2025

The X-ray Imaging Spectroscopy Mission (XRISM) provides the best spectral resolution with which to study Sulfur (S) K-shell photoabsorption features from the interstellar medium (ISM).

Synthetic ice spectra of a ‘simple’ ice composition

Astrochemistry, Astronomy & Telescopes, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Status Report

Predicting the Detectability of Sulphur-bearing Molecules in the Solid Phase with Simulated Spectra of JWST Instruments

by Keith CowingFebruary 14, 2025February 14, 2025

To date, gas phase observations of sulphur in dense interstellar environments have only constrained the molecular carriers of ∼ 1 % of its predicted cosmic abundance. An additional ∼ 5 […]

Composite image of a star-forming region (left) and Comet 67P (right). In the center is the ammonium hydrosulfide salt (NH4SH) that both appear to have in common, and which explains, among other things, why there is less volatile sulfur in star-forming regions than expected. (c) NASA/ESA/CSA/M. Zamani (ESA/Webb); ESA/Rosetta/NAVCAM; K. Slavicinska.

Astrochemistry, Astrogeology, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Interstellar, Press Release

Lost Sulfur In The Universe Found In Salt On Dust And Pebbles

by Keith CowingFebruary 3, 2025February 2, 2025

An international team led by astronomers at Leiden University has shown in laboratory experiments that sulfur can bind with ammonium under icy cosmic conditions and form a salt that sticks […]

Sulfur distribution on the surface of Mercury expressed as S/Si (Nittler et al., 2020). The highest S abundances 90 degrees west at the equator and north of it coincides with the highest Ca and Mg abundances, referred to as the high magnesium region (HMR) (reproduced from Nittler et al., 2020). -- astro-ph.EP

Astrochemistry, Astrogeology, Lava / magma ocean / Volcanic Worlds, Mapping, Geodesy, Cartography, Bathymetry, Mercury, Moon, Status Report

Sulfur In The Moon And Mercury

by Keith CowingOctober 29, 2024October 29, 2024

This chapter presents a comprehensive overview of the abundances and distribution of S, and the processes that control the behavior of S on the Earth’s Moon and on Mercury. The […]

A schematic diagram of the sulfur cycle on the icy Galilean moons. Not all processes operate on all moons and the circles with E, G, and C indicate which processes seem to be more restricted to Europa, Ganymede, and Callisto, respectively. Ice radiolysis happens on all icy surfaces and reactions of radiolytically produced H2SO4 can transform brine salts to sulfates. Only for Europa and Callisto the subsurface ocean is likely to be in contact with the rocky ocean floor but not for Ganymede, where massive dense ice layers prevents ongoing exchange of the subsurface with the silicates. The ocean compositions seem to be all quite similar in the beginning, and Ganymede’s ocean might be the oldest ur-ocean remaining since isolation by dense ice. Subsurface oceans on Europa and Callisto can evolve depending on silicate mantle outgassing into the oceans which may increase salinity over time. On Europa acidification from radiolytically produced H2SO4 may happen, which could lead to an ocean with compositional gradients and pH and development of a halocline. This diagram does not claim completeness and is an attempt to summarize observations, ideas and interpretations. -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Enceladus, Europa, Ganymede, Gas Giants, Icy Worlds, Imaging & Spectroscopy, Io, Jupiter, Mapping, Geodesy, Cartography, Bathymetry, Neptune, Saturn, Status Report, Titan, Uranus

Sulfur in the Giant Planets, their Moons, and Extrasolar Gas Giant Planets

by Keith CowingOctober 18, 2024October 18, 2024

We review sulfur chemistry of the gas giant planets and their moons where sulfur compounds are observed. The major S-bearing gas in the upper atmospheres of the giant planets is […]

Abundances of the ammonium cation w.r.t. H2O ice plotted against the τintC4/τintC3 ratios of ices toward isolated dense clouds (left, blue) and protostars (right, red). To facilitate comparison, the protostellar and cloud values are also plotted in the left and right plots, respectively, in light gray. A higher τintC4/τintC3 is indicative of a greater redshift in the peak position of the 6.85 μm feature. The plotted values are taken from Boogert et al. (2011) (clouds) and Boogert et al. (2008) (protostars). The Spearman’s rank correlation coefficient ρ and the p-value indicating probability of non-correlation are provided in the top right corner. The plotted NH4 + abundances have been multiplied by a correction factor of 4.4/3.6 to account for the difference between NH4+ ν4 mode band strength used by Boogert et al. (2008) and Boogert et al. (2011) (4.4×10-17 cm molec–1 from Schutte & Khanna 2003) and the band strengths calculated in this work to enable a direct comparison to our NH4+ ice upper limits in Table 5. Upper limits have been excluded from this plot, as well as data from the sources 2MASS J19214480+1121203 (due to the high error of its τintC4/τintC3 ratio) and IRAS 03301+3111 (due to its τintC4/τintC3 ratio being undefined because its τintC3 = 0). -- astro-ph.GA

Astrochemistry, Biochemistry & Organic Chemistry, Interstellar, Status Report

Ammonium hydrosulfide (NH4SH): A Potential Significant Sulfur Sink In Interstellar Ices

by Keith CowingOctober 7, 2024October 7, 2024

Sulfur is depleted with respect to its cosmic standard abundance in dense star-forming regions. It has been suggested that this depletion is caused by the freeze-out of sulfur on interstellar […]

Spectrum obtained 1.0 days after the first ZTF detection with Keck/LRIS in the range from 2,720 to 4,800 ˚A, after subtracting the blackbody continuum. The spectrum reveals narrow emission lines of highly ionised species of silicon, sulphur, and argon, which have never been seen in any SN before, as well as doubly ionised carbon, singly ionised magnesium, and neutral helium. A number of the highly ionised silicon and sulphur lines also exhibit P Cygni profiles with a maximum velocity of ∼ 3,000 km s−1 (Extended Material Figure 2), indicating that these lines are produced in a fast-moving, metal-rich CSM (e.g., a wind or a shell expelled by the progenitor shortly before the explosion). The spectrum is rebinned for illustration purposes. The lower bound of the ordinate axis was cropped for illustration purposes. -- astro-ph.HE

Astrochemistry, Astrogeology, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Interstellar, Status Report

A Cosmic Formation Site of Silicon and Sulphur Revealed by a New Type of Supernova Explosion

by Keith CowingSeptember 12, 2024September 12, 2024

The cores of stars are the cosmic furnaces where light elements are fused into heavier nuclei. The fusion of hydrogen to helium initially powers all stars. The ashes of the […]

Transmission spectra of L98-59 d obtained using transitspectroscopy (pink) and FIREFLy (blue) pipelines. The spectral light curves from the two indepedent reductions were fitted using juliet with a similar parametrization at pixel resolution and then binned to R ∼ 100. The residuals between the two reductions show a global offset between the two reductions for the NRS2 detector. -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Hints Of A Sulfur-rich Atmosphere Around the 1.6 R⊕ Super-Earth L98-59 d from JWST NIRSpec G395H Transmission Spectroscopy

by Keith CowingAugust 30, 2024August 29, 2024

Detecting atmospheres around planets with a radius below 1.6 R⊕, commonly referred to as rocky planets (Rogers_2015, Rogers_2021), has proven to be challenging. However, rocky planets orbiting M-dwarfs are ideal […]

Structures of all the target molecules considered in this work. -- astro-ph.GA

Astrochemistry, Astrogeology, Astronomy & Telescopes, Imaging & Spectroscopy, Status Report

Where Have All the Sulfur Atoms Gone? Polycyclic Aromatic Hydrocarbon as a Possible Sink for the Missing Sulfur in the Interstellar Medium. I. The C–S Band Strengths

by Keith CowingAugust 13, 2024August 13, 2024

Despite its biogeneic and astrochemical importance, sulfur (S), the 10th most abundant element in the interstellar medium (ISM) with a total abundance of S/H~2.2E-5, largely remains undetected in molecular clouds.