![Proposed reaction network for the radiolysis of PCN:N2 ice by 40 MeV 40Ar9+ ions at 10 K. The scheme summarizes the main fragmentation, radical recombination, isomerization, and nitrogen incorporation pathways inferred from the infrared identifications and kinetic analysis. The radicals shown in the "Primary fragmentation" box are representative examples of how reactive intermediates are inferred from the experimental results and do not constitute an exhaustive list of all fragments produced during irradiation. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Formation.png?resize=1200%2C706&ssl=1)
[astro-ph.EP] Context. Nitriles are key nitrogen-bearing organic molecules in dense clouds, star-forming regions, and nitrogen-rich icy environments. Understanding their stability and chemical evolution under energetic processing is essential for understanding […]
astrochemistry
![Simulated results with NewAthena/X-IFU (400ks exposure, binning factor 3). Figure (a) and (b) plotted the dust model against simulated data (sim. data) along the line of sight from GX 340+00 and GX 5-1, respectively. Figure (c) displays the comparison of three silicate models in GX 13+. -- [astro-ph.GA]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Investigation.png?resize=1200%2C726&ssl=1)
Posted inAstrochemistry
Investigation Of Calcium Dust In The Interstellar Medium
[astro-ph.GA] Calcium is a highly depleted element in the interstellar medium (ISM), however its composition in the solid phase remains elusive. The detection of Ca-bearing dust has been limited due […]
![Computed abundance maps of ammonium cyanate, ammonium formate, ammonium acetate, ammonium hydrosulfide and ammonium carbamate in the solid phase for r < 50 au and computed after 1 Myr and 10 Myrs. We also show the ratio of the vertically integrated abundances of these salts relative to water ice. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Ammonium-salt-.png?resize=1200%2C720&ssl=1)
Posted inAstrochemistry
Ammonium Salt Formation And Abundance In Protoplanetary Disks
[astro-ph.EP] Ammonium salts may represent an important reservoir of volatile species in Solar system primitive bodies, but the question of how and when these salts can form during the star […]
Posted inComets and Asteroids
A JWST Study of Stardust. I. Infrared Spectroscopy of Comet 81P/Wild 2 and Overall Composition
[astro-ph.EP] We report observations of comet 81P/Wild 2, target of the Stardust sample return mission, on UT 2023 March 20 and 24 at a heliocentric distance (rH) of 1.85 au […]
Posted inComets and Asteroids
Gelato: A Mission Concept for Comet Surface Sample Return
[The Planetary Science Journal] Understanding the role of comets in solar system formation and evolution has continued to be a driving question in planetary science. It is believed that comets […]
Posted inAstrochemistry
Chemical Modelling Of Interstellar MgS
[astro-ph.GA] The detection of magnesium sulphide (MgS) and sodium sulphide (NaS) towards the Galactic Center molecular cloud G+0.693 constitutes the first detection of metal sulphides in the interstellar medium (ISM).
![Schematic diagram of our spectral line stacking and matched filtering procedures. First, (a) shows relevant spectral regions of the (synthetic) observational data (black) and an initial spectral simulation (red). Each spectral window is then weighted based on the signal-to-noise ratio of each region to create a velocity stack of all relevant molecular rotational transitions (b). Finally, the stacked simulation is used as a matched filter and is cross-correlated with the stacked data to visualize the statistical significance of a given detection (c). -- [astro-ph.GA]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Exploring-the-Limits.png?resize=1200%2C720&ssl=1)
Posted inAstrochemistry
Exploring the Limits of Spectral Line Stacking in Spectral Line Data and Application Toward the Detection of Bulk 13C Enrichment of Aromatics in TMC-1
[astro-ph.GA] The formation history of polycyclic aromatic hydrocarbons (PAHs) in the interstellar medium remains a topic of active debate, with proposed mechanisms ranging from high-temperature stellar ejecta processes to low-temperature […]
![Helicity asymmetries of the primordial (left panel) and late-time (right panel) density fields for parity asymmetric (blue curves) and symmetric (red curves) simulations. The shaded regions indicate the standard deviation (1σ) of the ensemble-average. The red markers highlight the asymmetries exceeding a statistical significance of 3σ. - [astro-ph.CO]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Probing.png?resize=1200%2C718&ssl=1)
Posted inAstrochemistry
Probing Primordial Chirality in the Matter Distribution
[astro-ph.CO] Whether parity symmetry was violated in the early universe remains one of the fundamental open questions in cosmology. If so, it may leave an intrinsic handedness in the large-scale […]
![Three-dimensional thermal phase architecture of the local ISM. (a) Three-dimensional rendering of the cold (blue) and unstable (yellow) isosurfaces, with warm gas shown transparent. The transparent warm volume traces WNM together with unmodelled hot ionised gas, which carries negligible mass (Methods). An interactive version is available at https://sb2580.github.io/phases 3d/. (b) Slices through the Galactic plane (𝑧 = 0) of gas density 𝑛 (left), FUV radiation intensity 𝐼UV (middle), and phase classification (right). Concentric circles mark heliocentric radii of 150, 300, and 450 pc. -- [astro-ph.GA]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/The-first-three.png?resize=1200%2C719&ssl=1)
Posted inAstrochemistry
The First Three-dimensional Map Of Thermal Phases In The Local Interstellar Medium
[astro-ph.GA] The thermal state of interstellar gas controls whether it remains warm and diffuse or cools into dense clouds. Twentyone centimetre observations have established a statistical picture of neutral-gas phases, […]
Posted inAstrochemistry
An Interstellar Energetic And Non-aqueous Pathway To Peptide Formation
[astro-ph.SR] The origin of the molecular building blocks of life is a central question in science. A few α-amino acids such as glycine, the simplest proteinogenic amino acid, have been […]