![Effect of substrate morphology and composition on the UV photodesorption of water ice at 12 K. (A) Evolution of the XPS-derived ice coverage as a function of photon fluence for an initial coverage of approximately 4 ML deposited on planar gold, planar olivine crystal, olivine microparticle powder, and soot at 12 K. Linear fits to the coverage curves give photodesorption yields of 1.5 × 10−3 , 1.8 × 10−3 , 7.2 × 10−4 , and 7.2 × 10−5 molecule photon−1 , respectively (see Table 1). (B) Scanning electron microscopy image of the olivine powder film, showing micrometer- and submicrometer-sized angular particles. (C) Scanning electron microscopy image of the soot film, showing highly aggregated carbon nanoparticles with a much finer and more ramified morphology. (D) Coverage derived from XPS measurements as a function of UV fluence at 12 K for 2 ML ice films deposited at 120 K (nonporous ice) and 12 K (porous ice), giving photodesorption yields of 4.6 × 10−5 and 1.4 × 10−5 molecule photon−1 , respectively -- [astro-ph.IM]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/11/Suppression.png?resize=1200%2C720&ssl=1)
[astro-ph.IM] Ultraviolet (UV) photodesorption regulates the partitioning of water between interstellar ice mantles and the gas phase, yet laboratory yields are generally measured on planar substrates rather than on surfaces […]
Interstellar
Posted inAstrochemistry
Astrochemistry: Hubble and JWST Observe Star Formation in The Carina Nebula
[ESA] The NASA/ESA Hubble and the NASA/ESA/CSA James Webb Space Telescopes recently stared at an eerie star-forming scene within the Carina Nebula, a massive gas and dust cloud located approximately […]
![The PES for the reaction of C6H6 with CP in kcal mol−1 . Values in gray were calculated using CCSD(T)-F12c/cc-pVTZ-F12//ωB97X-2(TQZ)-D3(BJ)/ma-def2-TZVPP, those in orange were found using DFT alone (ωB97X-2(TQZ)-D3(BJ)/ma-def2-TZVPP), and those in navy blue were found using CCSD(T)-F12c/cc-pVTZ-F12//M06-2X-D3(0)/ma-def2-TZVPP. The dashed gray and navy lines corresponds to the identified transition states in the calculations which employed ωB97X-2(TQZ) and M06-2X, respectively. Meanwhile, the dotted black line represents the barrierless CP addition to benzene found from the relaxed scans that used ωB97X, ωB97M, and B2PLYP. -- [astro-ph.GA]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/11/A-Potential.png?resize=1200%2C720&ssl=1)
Posted inAstrochemistry
A Potential New Dimension of Astrophysical Aromatic Functionalization: Phosphaethynyl (CP) Derivatives
[astro-ph.GA] Quantum chemical computations outline a thermodynamically viable, low-temperature, gas-phase formation pathway for phosphaethynyl cyclopropenylidene (c-C3HCP), resulting from cyclopropenylidene (c-C3H2) and the phosphaethynyl (CP) radical.
Posted inAstrochemistry
Formamide Formation on Forsterite and Mg(OH)2.H2O
[astro-ph.GA] Context. Formamide formation in the Universe has been the subject of debate due to its importance as a precursor to amino acids and RNA. Current studies focus on the […]
Posted inAstrochemistry
Pre-Accretion Formation of Sulfuric Acid in Interstellar Ice Analogs: Implications for Sulfate in Ryugu and Bennu
[The Journal of Physical Chemistry Letters] Sulfate-bearing phases and soluble sulfate species, including sodium sulfate (Na2SO4), in carbonaceous asteroids are commonly attributed to parent-body aqueous alteration, yet the formation of […]
![Proposed scenario to explain the hydrocarbon-rich spectrum of HOPS-68. Gas-phase carbon-bearing species enrich the gas between the soot line (∼ 500 K) and the graphite sublimation rim (∼ 1200 K), which we refer to as the "refractory carbon destruction zone", and are then entrained and transported out of the disk by the disk wind. In the outflow cavity, C2H2 reacts with UV-photons, with C2H as reaction product. C2H can react with C2H2 to form carbon-chain species such as C4H2 and C6H2. The location of the isotherms were estimated using the results from paper A.-- [astro-ph.SR]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/11/Up-in-smoke.png?resize=1200%2C720&ssl=1)
Posted inAstrochemistry
Up In Smoke: Carbon-destruction In The Terrestrial Planet-forming Region Of A Young Class I Disk
[astro-ph.SR] Earth’s surface and deep mantle are strongly depleted in carbon compared to the Sun. Sublimation of solid carbonaceous material in the inner midplanes of young disks could cause this […]
Posted inAstrochemistry
Does Topology-Dependent Chemistry Influence the Interstellar PAH Inventory? Insights from the Absence of Cyanotriphenylenes
[astro-ph.GA]. Although a set of polycyclic aromatic hydrocarbons (PAHs) has recently been identified in the cold dark cloud TMC-1, several common PAH motifs remain absent, leaving the origin of this […]
![Moment 0 maps of the transitions of CH3OH at 282213.3 MHz (Eup = 341 K, Aij = 9 × 10−7 s−1) and 281000.1 MHz (Eup = 191 K, Aij = 4 × 10−5 s−1), 13CH3OH at 283207.3 MHz (two transitions with Eup = 95 and 110 K, Aij = 7 × 10−5 s−1), CH18 3 OH at 309979.3 MHz (Eup = 77 K, Aij = 3 × 10−4 s−1 ), CH3OD at 291412.8 MHz (Eup = 161 K, Aij = 1 × 10−4 s−1 ), CH2DOH at 279335.7 MHz (Eup = 132 K, Aij = 3 × 10−5 s−1 ), CHD2OH at 296460.6 MHz (Eup = 108 K, Aij = 7 × 10−5 s−1 ), and CD3OH at 305957.8 MHz (Eup = 163 K, Aij = 2 × 10−4 s−1 ). The integration was done between -9 and 0 km s−1. The continuum peak (C) and the blueshifted (B) and the redshifted (R) positions are indicated with crosses. The directions of the blueshifted and redshifted outflows are indicated with cyan and orange arrows, respectively. The 0,0 position is the continuum peak position. [astro-ph.GA]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/11/complex.png?resize=1200%2C719&ssl=1)
Posted inAstrochemistry
Complex Organic Molecules in Protostars with ALMA Spectral Surveys (COMPASS) III. CH3OH isotopic fractionation in the low-mass protostar BHR71-IRS1
[astro-ph.GA]. [Abridged] Methanol is a complex organic molecule detected in both ice and gas toward star-forming regions. Due to its high abundance, its rarer isotopologues, including the deuterated ones, are […]
Posted inAstrochemistry
Astrochemistry: Dwarf Galaxies Retain Only A Small Fraction Of The Oxygen Made By Their Stars
[NASA/STSCI] NASA’s Hubble Space Telescope just revealed a mystery in our cosmic neighborhood. In a paper published Monday in The Astrophysical Journal, researchers using Hubble studied 37 nearby dwarf galaxies […]
Posted inComets and Asteroids
Comprehensive Visible and Near-infrared Keck and Gemini Monitoring and Characterization of Interstellar Comet 3I/ATLAS during its Encounter with the Solar System
[astro-ph.EP] We present 14 optical imaging and eight optical spectroscopic epochs of interstellar comet 3I/ATLAS from Keck/LRIS and Gemini/GMOS, two near-infrared (NIR) imaging epochs from Keck/MOSFIRE, and four NIR spectroscopic […]