Year: 2025
Type: article
Abstract: There is a long-standing discussion in the astrophysical/astrochemical community as to the structure and morphology of dust grains in various astrophysical environments (e.g., interstellar clouds, protostellar envelopes, protoplanetary and debris disks, and the atmospheres of exoplanets). Typical grain models assume a compact dust core which becomes covered in a thick ice mantle in cold dense environments. In contrast, less compact cores are likely to exhibit porosity, leading to a pronounced increase in surface area with concomitant much thinner ice films and higher accessibility to the bare grain surface. Several laboratory experimental and theoretical studies have shown that this type of dust structure can have a marked effect on several physico-chemical processes, including adsorption, desorption, mobility, and reactivity of chemical species. Porous grains are thus thought to likely play a particularly important and wide-ranging astrochemical role. Herein, we clarify what is meant by porosity in relation to grains and grain agglomerates, assess the likely astrochemical effects of porosity and ask whether a fractal/porous structural/morphological description of dust grains is appropriate from an astronomical perspective. We provide evidence for high porosity from laboratory experiments and computational simulations of grains and their growth in various astrophysical environments, and assess the observational constraints and perspectives on cosmic dust porosity. Overall, our paper discusses the effects of including porosity in dust models and the need to use such models for future astrophysical, astrochemical and astrobiological studies involving surface or solid-state processes.
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $5,290
Funders: National Science Foundation, National Aeronautics and Space Administration, Friedrich-Schiller-Universität Jena, UK Research and Innovation, European Commission, Deutsche Forschungsgemeinschaft, Generalitat de Catalunya, Ministerio de Ciencia e Innovación, HORIZON EUROPE Framework Programme, Engineering and Physical Sciences Research Council, Japan Society for the Promotion of Science
Awards: 現実的なダスト光学特性モデルの開拓と原始惑星系円盤の多波長観測への応用, G1074069453, G1089102518, Dynamical and chemical modeling of low-mass star-forming cores, G1510469474, Astrocatalysis: In Operando Studies Of Catalysis And Photocatalysis Of Space-abundant Transition Metals, G1648629719, G2543706835, G2907678734, すばる望遠鏡と赤外波面センサー補償光学による原始惑星系円盤の水氷観測, G4181574914, G4576373267, G4643791638, G4723939296, G5552848210, G6438359004, G6675271965, G6737866374, G6760653515, G6874468849, G7151044730, G7634998642, G8373511800, G8418175817
OpenAlex ID: W4415412533