![Herschel H2 column density map (Sadavoy et al. 2012) of Perseus starless and prestellar cores. Labeled in magenta are the locations and names of the 15 starless and prestellar cores analyzed. The star-forming regions within Perseus are denoted in black.-- [astro-ph.GA]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Inventories.png?resize=1200%2C716&ssl=1)
[astro-ph.GA] Carbon-chain molecules serve as an important reservoir of reactive organic matter that will eventually be incorporated into protoplanetary disks, planets, and cometary material. Prestellar and starless cores are composed […]
Astrochemistry
Posted inAstrochemistry
Variations in the 3.3 µm Polycyclic Aromatic Hydrocarbon Feature Across Nearby Galaxies Driven by Metallicity and Radiation Field Spectrum
[astro-ph.GA] We use JWST NIRCam imaging to investigate the 3.3 μm polycyclic aromatic hydrocarbon (PAH) feature in nearby galaxies. NIRCam observations of the 3.3 μm feature are emerging as a […]
![Vertical cut through the best-fit disk model on a logarithmic radial scale. Shown are temperatures, where the gas density, ϱdisk, exceeds an assumed ISM density of ϱISM = 2.7 × 10−24 g cm−3 (Ferrière 2001) by a factor of 1000. The snowline at Tsnow = 170 K and the 100 K-line, as well as the unity optical depth lines at a wavelength of 3.1 µm (computed for the best-fit model described in Sect. 5.2.2) measured from the star to the observer and from observer to the star, illustrate the temperature and dust density structure of the disk. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Spatial.png?resize=1200%2C715&ssl=1)
Posted inAstrochemistry
Spatial Distribution Of Water Ice In The Protoplanetary Silhouette Disk d216-0939
[astro-ph.EP] The composition of rocky planets depends on the dust in their natal protoplanetary disk (PPD), potentially containing water ice. Crystalline water ice was detected in the PPD d216-0939 in […]
![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)
Posted inAstrochemistry
Formation Of Nitriles And Isonitriles By The Heavy-ion Irradiation Of Propionitrile In N2-rich Astrophysical Ices
[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 […]
![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 […]