organic chemistry Archives

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Comets and Asteroids, Status Report

Phosphorus-rich Grains In Ryugu Samples With Major Biochemical Potential

by Keith CowingOctober 14, 2024

Parent bodies of C-type asteroids may have brought key volatile and organic-rich compounds to the terrestrial planets in the early stages of the Solar System. At the end of 2020, […]

Overview of our models for gas disk and particles evolution in different disk regions. The blue and yellow particles represent silicates with and without refractory carbon. The light blue particles represent icy pebbles. The pink particles show the oxygen atoms which are formed by the destruction of oxygen molecules because of the FUV radiation which is described as red arrows. The light blue dashed line is the snow line. Icy pebbles enclosing many small silicates drift to the snow line (blue dashed line) from the outer region. Orange upper and lower layers are FUV-exposed regions, where oxygen atoms exist. -- astro-ph.EP

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Habitable Zones, Imaging & Spectroscopy, Interstellar, Status Report

Effect of Different Stickiness Between Icy and Silicate Particles on Carbon Depletion in Protoplanetary Disks

by Keith CowingOctober 12, 2024October 12, 2024

Earth and other rocky bodies in the inner Solar System are significantly depleted in carbon compared to the Sun and interstellar medium (ISM) dust.

Hycean and mini-Neptune scenarios with two photochemical models. Top row: Original simulations from Wogan et al. (2024), showing the mixing ratio of molecules against atmospheric pressure in bar. Bottom row: VULCAN simulations of the same scenarios with equivalent assumptions (see main text). The scenarios are: an uninhabited Hycean (left column), an inhabited Hycean (middle column), and a mini-Neptune case (right column). The given molecular constraints are from the “One offset” case (Madhusudhan et al. 2023b) as this case gives the best fit to the observed data. 1-σ error bars are given for detected molecules (CH4 - orange; CO2 - green), and 2-σ upper limits are given for CO (purple), H2O (blue), and NH3 (grey), which were not detected by Madhusudhan et al. (2023b). The photosphere, the region in the atmosphere which impacts the transmission spectrum observed, is given in a light grey shade between 10−2 – 10−4 bar. A variety of simulations were run with both the W24 setup (see Table A1) and VULCAN (see Table A2). All of the simulations shown in this figure use the GJ 176 spectrum. Only the inhabited Hycean scenarios in both models are consistent with the retrieved abundances. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Status Report, Water/Hycean Worlds & Oceanography

Considerations for Photochemical Modeling of Possible Hycean Worlds

by Keith CowingOctober 11, 2024September 18, 2025

JWST is revolutionising the study of temperate sub-Neptunes, starting with the first detection of carbon-bearing molecules in the habitable-zone sub-Neptune K2-18 b. The retrieved abundances of CH4 and CO2 and […]

IR difference spectra obtained upon 2 keV electron irradiation of a 13C 18O:CS2 ice sample at 7 K (Exp. 7). IR band assignments are indicated for the initial ice components (black), and ice chemistry products (blue), including the OCS isotopologs (red). -- astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Icy Worlds, Imaging & Spectroscopy, Interstellar, Status Report

Ice Origins of OCS and Chemistry of CS2-bearing Ice Mantles

by Keith CowingOctober 11, 2024

Understanding the formation of carbonyl sulfide (OCS) in interstellar ices is key to constrain the sulfur chemistry in the interstellar medium (ISM), since it is the only ice S-bearing molecule […]

CO and PAH emission in one nearby galaxy. The left panel shows an inclination-corrected ALMA CO(2-1) image of NGC 2903 with contours at 1.25, 3.1, 31, and 100 K km s−1 . The right panel shows a predicted CO(2-1) intensity map based on JWST F770WPAH and the prescription in Eq. 5. The contours are the same as on the left panel, and they show a very close correspondence between CO and PAH emission. At the same time, CO(2-1) emission is underestimated in the bar ends, highlighting improvements to be explored in future work. This figure also shows the improved sensitivity of JWST compared to ALMA at recovering faint emission, with the 5σ RMS noise indicated on each colorbar. -- astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Interstellar, Status Report

Polycyclic Aromatic Hydrocarbon and CO(2-1) Emission at 50-150 pc Scales in 66 Nearby Galaxies

by Keith CowingOctober 10, 2024October 10, 2024

Combining Atacama Large Millimeter/sub-millimeter Array CO(2-1) mapping and JWST near- and mid-infrared imaging, we characterize the relationship between CO(2-1) and polycyclic aromatic hydrocarbon (PAH) emission at ~100 pc resolution in […]

Strand separation by salt cycling -- eLife

Astrochemistry, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report

Prebiotic Gas Flow Environment Enables Isothermal Nucleic Acid Replication

by Keith CowingOctober 9, 2024October 9, 2024

Nucleic acid replication is a central process at the origin of life. On early Earth, replication is challenged by the dilution of molecular building blocks and the difficulty of separating […]

GOTHAM spectra showcasing several 1-cyanopyrene lines detected in TMC-1 observations. The original GOTHAM observational data for which one channel corresponds to 1.4 kHz were smoothed with a Hanning window to a resolution of 14 kHz, depicted in black. The spectrum of 1-cyanopyrene is overplotted in violet using source-dependent molecular parameters as reported in Table S4. The quantum numbers of each transition, ignoring 14N nuclear electric quadrupole splitting, are reported. Each line contains multiple closely spaced K-components of each transition which are denoted α, β, γ, δ = {0,1}, {1,2}, {2,3}, {3,4}. -- astro-ph.GA

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Comets and Asteroids, Imaging & Spectroscopy, Interstellar, Sample Return, Status Report

Discovery Of Interstellar 1-cyanopyrene: A Four-ring Polycyclic Aromatic Hydrocarbon In TMC-1

by Keith CowingOctober 5, 2024October 7, 2024

Polycyclic aromatic hydrocarbons (PAHs) are thought to be the most abundant class of molecules in space, yet their interstellar lifecycle is poorly understood due to difficulties detecting individual PAHs.

Velocity-stacked spectra and matched filter responses of 2- and 4-cyanopyrene. The stacked GOTHAM observations (black) are overlaid with the simulated stacked spectrum of 2- and 4-cyanopyrene (blue and pink, respectively), each consisting of the 150 brightest SNR lines (left panels). Marginalized posterior parameters were used in both simulations, as reported in Supplementary Table A3. The corresponding impulse response for the matched filtering analysis is shown, yielding a significance of 8.0 σ and 12.9 σ for the 2- and 4-cyanopyrene detections, respectively (right panels). The small features in the stacked simulated spectrum (pink) in the bottom left panel result from the densely populated 4-cyanopyrene lines (see Fig. A3) that add up in the stack. -- astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Comets and Asteroids, Imaging & Spectroscopy, Meteorites & Asteroids, Status Report

Detections Of Interstellar 2-cyanopyrene And 4-cyanopyrene In TMC-1

by Keith CowingOctober 4, 2024October 8, 2024

Polycyclic aromatic hydrocarbons (PAHs) are among the most ubiquitous compounds in the universe, accounting for up to ~25% of all interstellar carbon. Since most unsubstituted PAHs do not possess permanent […]

The emergence of life from nonlife -- Grok via Astrobiology.com

Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Origin & Evolution of Life, Status Report

A Bayesian Analysis Of The Probability Of The Origin Of Life Per Site Conducive to Abiogenesis

by Keith CowingOctober 4, 2024October 4, 2024

The emergence of life from nonlife, or abiogenesis, remains a fundamental question in scientific inquiry. In this article, we investigate the probability of the origin of life (per conducive site) […]

A close-up view of an engineering model of SHERLOC (Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals), one the instruments aboard NASA's Perseverance Mars rover. NASA/JPL-Caltech

Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Habitable Zones, Imaging & Spectroscopy, Mars, Status Report

Investigating The Stability of Aromatic Carboxylic Acids in Hydrated Magnesium Sulfate under UV Irradiation to Assist Detection of Organics on Mars

by Keith CowingOctober 4, 2024

The Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) instrument onboard the Mars 2020 Perseverance rover detected so far some of the most intense fluorescence signals […]

organic chemistry

Phosphorus-rich Grains In Ryugu Samples With Major Biochemical Potential

Effect of Different Stickiness Between Icy and Silicate Particles on Carbon Depletion in Protoplanetary Disks

Considerations for Photochemical Modeling of Possible Hycean Worlds

Ice Origins of OCS and Chemistry of CS2-bearing Ice Mantles

Polycyclic Aromatic Hydrocarbon and CO(2-1) Emission at 50-150 pc Scales in 66 Nearby Galaxies

Prebiotic Gas Flow Environment Enables Isothermal Nucleic Acid Replication

Discovery Of Interstellar 1-cyanopyrene: A Four-ring Polycyclic Aromatic Hydrocarbon In TMC-1

Detections Of Interstellar 2-cyanopyrene And 4-cyanopyrene In TMC-1

A Bayesian Analysis Of The Probability Of The Origin Of Life Per Site Conducive to Abiogenesis

Investigating The Stability of Aromatic Carboxylic Acids in Hydrated Magnesium Sulfate under UV Irradiation to Assist Detection of Organics on Mars

The First Selection Of Optimal Targets For The Lazuli ExtraSolar Coronagraph’s Reflected Starlight Exoplanet Campaign

Paleo-heat Flux Estimates Across Enceladus Derived From Flexural Response Of The Ice Shell

Astrobiologist Dale Andersen’s Antarctic Field Report: 26 October 2026: Flying South

Complex Organic Molecules in Protostars with ALMA Spectral Surveys (COMPASS): I. Overview of the ALMA Large Program

A Technical Reanalysis Of The Viking Carbon Assimilation-Pyrolytic Release Experiment