XUE: Thermochemical Modeling Suggests a Compact and Gas-depleted Structure for a Distant, Irradiated Protoplanetary Disk
Year: 2025
Type: article
Abstract: Unveiling the physical structure of protoplanetary disks is crucial for interpreting the diversity of the exoplanet population. Until recently, the census of the physical properties of protoplanetary disks probed by mid-infrared observations was limited to the solar neighborhood (d ≲ 250 pc). However, nearby star-forming regions (SFRs) such as Taurus—where no O-type stars reside—are not representative of the environments where the majority of the planet formation occurs in the Galaxy. The James Webb Space Telescope (JWST) now enables observations of disks in distant high-mass SFRs, where strong external far-ultraviolet radiation is expected to impact those disks. Nevertheless, a detailed characterization of the population of externally irradiated disks is still lacking. We use the thermochemical code ProDiMo to model JWST/MIRI spectroscopy and archival visual/near-infrared photometry aiming to constrain the physical structure of the irradiated disk around the solar-mass star XUE 1 in NGC 6357 (d ≈ 1690 pc). Our findings are as follows. (1) Mid-infrared dust emission features are explained by amorphous and crystalline silicates with compositions similar to nearby disks. (2) The molecular features detected with MIRI originate within the first ∼1 au, consistent with results from slab models. (3) Our model favors a disk truncated at 10 au with a gas-to-dust ratio of unity in the outskirts. (4) Comparing models of the same disk structure under different irradiation levels, we find that strong external irradiation raises gas temperature tenfold and boosts water abundance beyond 10 au by a factor of 100.
Source: The Astrophysical Journal
Authors: Bayron Portilla-Revelo, Konstantin V. Getman, María Claudia Ramírez-Tannus, Thomas J. Haworth, Rens Waters, Arjan Bik, Eric D. Feigelson, Inga Kamp, Sierk E. van Terwisga, Jenny Frediani, Thomas Henning, Andrew J. Winter, Veronica Roccatagliata, Thomas Preibisch, E. Sabbi, Peter Zeidler, Michael A. Kuhn
Institutions: Pennsylvania State University, Max Planck Institute for Astronomy, Queen Mary University of London, Radboud University Nijmegen, Space Research Organisation Netherlands, Stockholm University, AlbaNova, University of Groningen, Austrian Academy of Sciences, Space Research Institute, Centre National de la Recherche Scientifique, Université Côte d'Azur, Lagrange Laboratory, Observatoire de la Côte d’Azur, Arcetri Astrophysical Observatory, National Institute for Astrophysics, University of Bologna, Ludwig-Maximilians-Universität München, NSF NOIRLab, International Gemini Observatory, Space Telescope Science Institute, University of Hertfordshire
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funders: National Science Foundation, National Aeronautics and Space Administration, Space Telescope Science Institute, UK Research and Innovation, European Commission, Deutsche Forschungsgemeinschaft, Swedish National Space Agency, Deutsches Zentrum für Luft- und Raumfahrt, Bundesministerium für Wirtschaft und Energie, HORIZON EUROPE Framework Programme, Agencia Estatal de Investigación
Awards: G1175115578, G119436362, G1304755368, G1941877138, G210041235, G2262748287, G2340603345, G2469010403, G2521435125, G2601397997, G2608020247, G2650114919, G2756433129, G2945112853, G300979063, FOR 2634: Übergangsscheiben: Zeugen der Planetenentstehung, G34346518, G3480869486, G3681454997, G380733860, G4042783231, G4066435496, Physics and Chemistry of Planet-Forming Disks in Extreme Radiation Environments, G425668148, G434337789, EXC 2094: ORIGINS: Vom Ursprung des Universums bis zu den ersten Bausteinen des Lebens, G4526231891, G5080475149, G5195188938, G6051097380, G6101182835, G6115201310, G6858939331, G7084143925, G8118709007, G9000173888
OpenAlex ID: W4410522147