organic chemistry Archives

H2NC hyperfine lines observed towards G+0.693, corresponding to the 101 − 000 rotational transition (upper panel) and the 202 − 101 rotational transition (lower panel). Black histogram and grey-shaded areas indicate the observed spectrum, while the red and blue lines represent the best LTE fit obtained for H2NC, and the emission of all the species already identified in the cloud (whose names are indicated by the blue labels), respectively. Magenta vertical lines indicate those transitions selected to perform the AUTOFIT. The transitions shown are only those with peak intensities of 𝑇 ∗ A > 0.41 mK, which corresponds to 𝜎/3 value (where 𝜎 is the rms of the spectra). The spectroscopic information for the observed transitions is given in Table A1 of Appendix A. -- astro-ph.GA

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

H2CN/H2NC Abundance Ratio: A New Potential Temperature Tracer For The Interstellar Medium

by Keith CowingMay 9, 2023May 9, 2023

The H2NC radical is the high-energy metastable isomer of H2CN radical, which has been recently detected for the first time in the interstellar medium towards a handful of cold galactic […]

The x and y axes are offsets in arcmin from the central map position; the z axis is velocity in km s−1. The emission starts at the 5σ level for both tracers. The bright star-forming cloud DR21 and other dense molecular clouds are embedded in a large-scale cloud structure only visible in [CII] (dark blue). An interactive version of these plots is found at https://astro.uni-koeln.de/stutzki/research/feedback/animations -- Nature Astronomy

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

SOFIA Helps Complete Picture on Molecular Cloud Formation

by Keith CowingMay 3, 2023May 3, 2023

Molecular clouds — clumps of gas and dust in space, where molecules form — make up the densest regions of the Milky Way, but how they assemble is largely unknown.

Astrochemistry, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Origin & Evolution of Life, Press Release

Distinguishing Biotic vs. Abiotic Origins of ‘Bio’signatures: Clues from Messy Prebiotic Chemistry for Detection of Life in the Universe

by Keith CowingMay 1, 2023May 1, 2023

It is not a stretch to say that the search for extraterrestrial life is possibly the biggest of the cosmic endeavors that humankind has embarked upon.

The carbon chemistry of Model B as in Figure 4 but with α3 = 1 × 10−7 cm3s−1. Figure (b) is as (a) except that reaction (29) has been removed. Figure (c) is as (a) except that reactions (34), (35) and (36) have been removed. -- astro-ph.GA

Astrochemistry, Biochemistry & Organic Chemistry, Imaging & Spectroscopy, Interstellar, Press Release

New Bistable Solutions in Molecular Cloud Chemistry: Nitrogen and Carbon Autocatalysis

by Keith CowingMay 1, 2023May 1, 2023

We have investigated the chemistry of dense interstellar clouds and found new bistable solutions in the nitrogen and carbon chemistries.

Evolution of grain size distribution. We present the case for silicate, but a similar evolutionary sequence is also obtained for carbonaceous dust. The grain size distribution is multiplied by 푎 4 and divided by 푛H so that the resulting quantity is proportional to the dust mass in logarithmic bins per gas mass. The colour indicates the age as shown in the colour bar. The slope of the MRN grain size distribution is shown by the thin solid line for reference. -- astro-ph.GA

Astrochemistry, Astrogeology, Exoplanets, -moons, -comets, Status Report

Effects of Dust Grain Size Distribution on the Abundances of CO and H2 in Galaxy Evolution

by Keith CowingApril 28, 2023April 28, 2023

We model the effect of grain size distribution in a galaxy on the evolution of CO and H2 abundances. The formation and dissociation of CO and H2 in typical dense […]

Comparison between the observed molecular abundances with respect to CH3CN at each core (horizontal color lines) and the modeled ones (black solid lines). The red dashed lines indicate the temperature evolution. -- astro-ph.GA

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

Chemical Differentiation around Five Massive Protostars Revealed by ALMA -Carbon-Chain Species, Oxygen-/Nitrogen-Bearing Complex Organic Molecules

by Keith CowingApril 28, 2023April 28, 2023

We present Atacama Large Millimeter/submillimeter Array Band 3 data toward five massive young stellar objects (MYSOs), and investigate relationships between unsaturated carbon-chain species and saturated complex organic molecules (COMs). An […]

Mass–radius for USP planets, with mass–radius measurements better than 25 per cent from http://www.astro.keele.ac.uk/jkt/tepcat/ and for our USP TESS candidates (see Table 1), colour coded by their equilibrium temperature. Two-layer models from Zeng et al. (2016) are displayed with different lines and colours. ‘Earth-like’ here means a composition of 30 per cent Fe and 70 per cent MgSiO3, whereas ‘100 per cent Rock’ means a composition of 100 per cent MgSiO3. Earth and Venus are identified in this plot as pale blue and orange circles, respectively -- astro-ph.EP

Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report

Surface Pressure Impact On Nitrogen-dominated USP Super-Earth Atmospheres

by Keith CowingApril 18, 2023April 18, 2023

In this paper, we compare the chemistry and the emission spectra of nitrogen-dominated cool, warm, and hot ultra-short-period (USP) super-Earth atmospheres in and out of chemical equilibrium at various surface […]

A new hypothesis states that the first sugars emerged from glyoxylate (pictured as the center molecule). In this hypothesis, glyoxylate first reacts with itself and then the byproducts from these reactions, ultimately forming simple sugars and other products (pictured as the surrounding molecules). CREDIT Scripps Research and Unsplash

Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Origin & Evolution of Life, Press Release

Where Did The First Sugars Come From?

by Keith CowingApril 13, 2023April 13, 2023

Two prominent origin-of-life chemists have published a new hypothesis for how the first sugars—which were necessary for life to evolve—arose on the early Earth.

A lightning strike in New Port Richey, Florida, led to a chemical reaction creating a new material, pictured here, that is transitional between space minerals and minerals found on Earth. CREDIT Matthew Pasek/University of South Florida

Astrochemistry, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Meteorites & Asteroids, Origin & Evolution of Life, Press Release

Lightning Strike Creates Phosphorus Material For The First Time On Earth

by Keith CowingApril 11, 2023April 11, 2023

After lightning struck a tree in a New Port Richey neighborhood, a University of South Florida professor discovered the strike led to the formation of a new phosphorus material. It […]

Potential energy surface of the CN + toluene reaction at the level of CCSD(T)/CBS//M06–2X-D3/6-311+G(d,p) in this work. The energetically favorable pathways are represented in red. Energies in parentheses are the results calculated at the level of M06-2X/aug-cc-pVTZ from Messinger et al. (Messinger et al. 2020). astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Imaging & Spectroscopy, Interstellar, Status Report, Titan

Reaction Kinetics Of CN + Toluene And Its Implication On The Productions Of Aromatic Nitriles In The Taurus Molecular Cloud And Titan’s Atmosphere

by Keith CowingApril 10, 2023April 10, 2023

Reactions between cyano radical and aromatic hydrocarbons are believed to be important pathways for the formation of aromatic nitriles in the interstellar medium (ISM) including those identified in the Taurus […]

organic chemistry

H2CN/H2NC Abundance Ratio: A New Potential Temperature Tracer For The Interstellar Medium

SOFIA Helps Complete Picture on Molecular Cloud Formation

Distinguishing Biotic vs. Abiotic Origins of ‘Bio’signatures: Clues from Messy Prebiotic Chemistry for Detection of Life in the Universe

New Bistable Solutions in Molecular Cloud Chemistry: Nitrogen and Carbon Autocatalysis

Effects of Dust Grain Size Distribution on the Abundances of CO and H2 in Galaxy Evolution

Chemical Differentiation around Five Massive Protostars Revealed by ALMA -Carbon-Chain Species, Oxygen-/Nitrogen-Bearing Complex Organic Molecules

Surface Pressure Impact On Nitrogen-dominated USP Super-Earth Atmospheres

Where Did The First Sugars Come From?

Lightning Strike Creates Phosphorus Material For The First Time On Earth

Reaction Kinetics Of CN + Toluene And Its Implication On The Productions Of Aromatic Nitriles In The Taurus Molecular Cloud And Titan’s Atmosphere

Astrobiologist Dale Andersen’s Antarctic Field Report: 20 Oct 2026: Wheels Down In Cape Town

Astrobiology Primer

The Evolution Of Oxygen, Temperature, And Marine Aerobic Habitat For Animals Over The Last Billion Years Of Earth History

Icy Ocean Planet Recon: Saildrone Research Fleet To Circle Antarctica For 5 Years

Water As We’ve Never Known It: Testing Water Beyond Earth-like Conditions