Interstellar Archives

Astronomers identified icy compounds made of complex organic molecules like alcohol and likely acetic acid, using MIRI, which was managed through launch by JPL.

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Habitable Zones, Imaging & Spectroscopy, Origin & Evolution of Life, Press Release

Webb Space Telescope Finds Ethanol And Other Organic Molecules Surrounding Young Protostars

by Keith CowingMarch 13, 2024March 13, 2024

What do margaritas, vinegar, and ant stings have in common? They contain chemical ingredients that NASA’s James Webb Space Telescope has identified surrounding two young protostars known as IRAS 2A […]

This image from NASA’s James Webb Space Telescope’s NIRCam (Near-Infrared Camera) of star-forming region NGC 604 shows how stellar winds from bright, hot, young stars carve out cavities in surrounding gas and dust. NASA, ESA, CSA, STScI

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

Astrochemistry: Peering Into The Tendrils Of NGC 604 With Webb Space Telescope

by Keith CowingMarch 12, 2024March 12, 2024

The formation of stars and the chaotic environments they inhabit is one of the most well-studied, but also mystery-shrouded, areas of cosmic investigation. The intricacies of these processes are now […]

Top left panel (a): Comparison of the UV absorption of indene with an elevated value at λ < 0.19 µm (“higher Cabs”; black long-dashed line) and that with the absorption at λ < 0.19 µm extrapolated from that at λ > 0.19 µm (“lower Cabs”; magenta dashed line). The UV absorption at λ > 0.19 µm for both cases is the same as Figure 1. Bottom left panel (b): Comparison of the MMP83 interstellar radiation field (red) with the radiation fields represented by different stellar effective temperatures (Teff = 40, 000 K: blue; Teff = 22, 000 K: cyan; and Teff = 8, 000 K: green). All the radiation intensities are normalized at λ = 0.2 µm. Right panel (c): Comparison of the model IR emission spectrum of indene in the diffuse ISM calculated with an elevated UV absorption at λ < 0.19 µm (dashed blue line) and that with the extrapolated UV absorption at λ < 0.19 µm (solid red line). -- astro-ph.GA

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

Infrared Emission of Specific Polycyclic Aromatic Hydrocarbon Molecules: Indene

by Keith CowingMarch 12, 2024March 12, 2024

Polycyclic aromatic hydrocarbon (PAH) molecules have long been suggested to be present in the interstellar medium (ISM). Nevertheless, despite their expected ubiquity and sustained searching efforts, identifying specific interstellar PAH […]

Left panel (a): Comparison of the IR emission spectra of 1-CNN of a natural line width of γ = 30 cm−1 (red line) for each vibrational transition with that of γ = 10 cm−1 (blue line). The molecule is illuminated by the MMP83 (U = 1) interstellar radiation field. Right panel (b): Same as (a) but for a comparison of γ = 30 cm−1 (red line) with γ = 50 cm−1 (blue line). - astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Biogeochemical Cycles & Geobiology, Imaging & Spectroscopy, Interstellar, Status Report

Infrared Emission of Specific Polycyclic Aromatic Hydrocarbon Molecules: Cyanonaphthalenes

by Keith CowingMarch 12, 2024March 12, 2024

The unidentified infrared emission (UIE) features at 3.3, 6.2, 7.7, 8.6, 11.3 and 12.7 micron are ubiquitously seen in a wide variety of astrophysical regions and commonly attributed to polycyclic […]

Spectrum towards all of our target sources between 256.1 GHz and 258 GHz. The filled grey histograms show the spectra, while the coloured labels show the detected transitions of all the light molecules and some transitions arising from COMs. The green line represents the LTE model fitted with Weeds. -- astro-ph.GA

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

Complex Organic Molecules Uncover Deeply Embedded Precursors Of Hot Cores

by Keith CowingMarch 12, 2024March 12, 2024

During the process of star formation, the dense gas undergoes significant chemical evolution leading to the emergence of a rich variety of molecules associated with hot cores and hot corinos. […]

The area near the seismic station in Manus Island, based on satellite images acquired on March 24, 2023 CREDIT Roberto Molar Candanosa and Benjamin Fernando/Johns Hopkins University, with imagery from CNES/Airbus via Google.

Astrogeology, Interstellar, Meteorites & Asteroids, Press Release, SETI & Technosignatures

Interstellar Signal Linked To Aliens Was Actually Just A Truck

by Keith CowingMarch 9, 2024March 9, 2024

Sound waves thought to be from a 2014 meteor fireball north of Papua New Guinea were almost certainly vibrations from a truck rumbling along a nearby road, new Johns Hopkins […]

Overview of reported 14N/ 15N ratios in HCN at various evolutionary stages from cores to disks. The majority of the measurements for HCN are derived using the indirect double isotope method; hence, a fixed 12C/ 13C ratio of 68 is assumed. Protoplanetary disks are abbreviated to PPDs in the figure. References are provided in Appendix A. -- astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Interstellar, Status Report

Fractionation In Young Cores: Direct Determinations Of Nitrogen And Carbon Fractionation In HCN

by Keith CowingMarch 9, 2024March 9, 2024

We aim to determine the 14N/15N and 12C/13C ratios for HCN in six starless and prestellar cores and compare the results between the direct method using radiative transfer modeling and […]

Comparison of the different abundance tables for every element, where ref 1:Anders & Grevesse (1989), ref 2:Grevesse & Sauval (1998), ref 3:Wilms et al. (2000), ref 4:Lodders (2003), ref 5 :Lodders & Palme (2009), ref 6:Asplund et al. (2009), ref 7:Asplund et al. (2021), ref 8:Nieva & Przybilla (2012). -- astro-ph.GA

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

Elemental Abundances In The Diffuse ISM From Joint FUV and X-ray Spectroscopy: Iron, Oxygen, Carbon and Sulfur

by Keith CowingMarch 6, 2024March 6, 2024

In this study, we investigate interstellar absorption lines along the line of sight toward the galactic low-mass X-ray binary Cygnus X-2. We combine absorption line data obtained from high-resolution X-ray […]

Evolution of the azimuthally averaged radial distributions of gas and dust parameters. The panels show (a) surface density of gas, (b) grown dust (including pebbles), (c) small dust, (d) maximum dust size, (e) dust-to-gas mass ratio, (f) surface density of pebbles, (g) maximum dust size relative to the fragmentation barrier, (h) Stokes number, (i) minimum pebble size. The solid blue line in panels (a) and (g) indicates the approximate disc boundary at Σg = 1g cm−2 , the dashed cyan line in panels (c)–(f), (h), and (i) shows the position of the water snowline. -- astro-ph.EP

Astrochemistry, Astrogeology, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Status Report

Ices On Pebbles In Protoplanetary Discs

by Keith CowingMarch 6, 2024March 6, 2024

The formation of solid macroscopic grains (pebbles) in protoplanetary discs is the first step toward planet formation. We aim to study the distribution of pebbles and the chemical composition of […]

Two-state formation channels for acetamide, N-methyl-formamide (NMF), and acetimidic acid. Two Cchannels are active, while the N2-channel leading to NMF are blocked by an energy barrier. -- chemrxiv.org

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Interstellar, Status Report

Spin-Forbidden Formation of Amide Molecules in the Interstellar Medium

by Keith CowingFebruary 27, 2024February 27, 2024

In this study, two-state spin-forbidden mechanisms are proposed for the barrierless formation of amide isomers in the C2H5NO family of molecules. This family belongs to the first level of complexity […]

Interstellar

Webb Space Telescope Finds Ethanol And Other Organic Molecules Surrounding Young Protostars

Astrochemistry: Peering Into The Tendrils Of NGC 604 With Webb Space Telescope

Infrared Emission of Specific Polycyclic Aromatic Hydrocarbon Molecules: Indene

Infrared Emission of Specific Polycyclic Aromatic Hydrocarbon Molecules: Cyanonaphthalenes

Complex Organic Molecules Uncover Deeply Embedded Precursors Of Hot Cores

Interstellar Signal Linked To Aliens Was Actually Just A Truck

Fractionation In Young Cores: Direct Determinations Of Nitrogen And Carbon Fractionation In HCN

Elemental Abundances In The Diffuse ISM From Joint FUV and X-ray Spectroscopy: Iron, Oxygen, Carbon and Sulfur

Ices On Pebbles In Protoplanetary Discs

Spin-Forbidden Formation of Amide Molecules in the Interstellar Medium

Relevance of the Avalon Assemblage as an Astrobiological Analog for Icy Ocean Worlds

The Climate and Potential Habitability of a Warm and Oxygenated Mars

Variable X-ray flux May Explain Variable Helium Escape From The Habitable-zone Exoplanet LHS 1140b

Spacetime Contactability in Galactic Civilization Networks: Contact Counts and Percolation

Surprisingly Enriched CO and CH4 in Halley-type Comet 13P/Olbers: Clues to Its Interstellar Heritage