SDSS-V LVM: Resolving physical conditions in the Trifid Nebula
Year: 2025
Type: article
Abstract: Aims . The chemical abundance of the interstellar medium sets the initial conditions for star formation and provides a probe of chemical galaxy evolution models. However, unresolved inhomogeneities in the electron temperature can lead to a systematic underestimation of the abundances. We aim to directly test this effect. Methods . We used the SDSS-V Local Volume Mapper to spatially map the physical conditions of the Trifid Nebula (M 20), a Galactic H II region ionized by a single mid-type O-star, at a 0.24 pc resolution. We exploited various emission lines (e.g., Hydrogen recombination lines and collisionally excited lines, including also faint auroral lines) and computed the spatially resolved maps of [O II ] and [S II ] electron densities, the [N II ], [O II ], [S II ], and [S III ] electron temperatures, and the ionic oxygen abundances. Results . We found internal variations of electron density that result from the ionization front, along with a negative radial gradient. However, we did not find any strong gradients or structures in the electron temperature and the total oxygen abundance, making the Trifid Nebula a relatively homogeneous H II region at the observed spatial scale. We compared these spatially resolved properties with equivalent integrated measurements of the Trifid Nebula and found no significant variations between integrated and spatially resolved conditions. Conclusions . This isolated H II region, ionized by a single O-star, represents a test case of an ideal Strömgren sphere. The physical conditions in the Trifid Nebula behave as expected, with no significant differences between integrated and resolved measurements.
Source: Astronomy and Astrophysics
Authors: Natascha Sattler, J. Eduardo Méndez-Delgado, Kathryn Kreckel, Christophe Morisset, Oleg Egorov, Evgeniya Egorova, Ahmad Nemer, Fu-Heng Liang, A. A. C. Sander, Alexandre Roman-Lopes, Carlos G. Román-Zúñiga, Evelyn J. Johnston, Sebastián F. Sánchez, José G. Fernández-Trincado, Niv Drory, Amrita Singh, Dmitry Bizyaev, Sumit K. Sarbadhicary, Pablo García, Alfredo Mejía-Narváez, Guillermo A. Blanc
Institutions: Heidelberg University, Universidad Nacional Autónoma de México, New York University Abu Dhabi, University of La Serena, Universidad Diego Portales, Instituto de Astrofísica de Canarias, Universidad Católica del Norte, McDonald Observatory, The University of Texas at Austin, University of Chile, New Mexico State University, Johns Hopkins University, The Ohio State University, Chinese Academy of Sciences, Chinese Academy of Science South America Center for Astronomy, National Astronomical Observatories, Carnegie Institution for Science
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
Funders: Bundesministerium für Wirtschaft und Klimaschutz, National Science Foundation, Smithsonian Institution, Alfred P. Sloan Foundation, Yale University, Carnegie Institution of Washington, Ohio State University, California Institute of Technology, Harvard University, Johns Hopkins University, New Mexico State University, Space Telescope Science Institute, Heising-Simons Foundation, Flatiron Health, Deutsche Forschungsgemeinschaft, École Polytechnique Fédérale de Lausanne, Deutsches Zentrum für Luft- und Raumfahrt, University of Toronto, Universidad Nacional Autónoma de México, Yunnan University, Nanjing University, China National Textile and Apparel Council, Leibniz-Institut für Astrophysik Potsdam, Agencia Nacional de Investigación y Desarrollo, Max-Planck-Institut für Astronomie, University of Illinois at Urbana-Champaign, University of Colorado Boulder, Smithsonian Astrophysical Observatory, European Research Council, Leibniz-Gemeinschaft, Dirección General de Asuntos del Personal Académico, Universidad Nacional Autónoma de México, National Astronomical Observatories, Chinese Academy of Sciences
Awards: G167639152, G2329447088, G2808433674, G3625898673, G3784803337, G3889686005, G411753437, G4792923422, G526559088, G5834573078, G6397868216, Entschlüsselung der Grundpfeiler unseres Universums: Anwendung und Entwicklung von Sternatmosphären der nächsten Generation, G6620179168, G7135376007, G8586566096, CENTRO DE ASTROFISICA Y TECNOLOGIAS AFINES (CATA)
OpenAlex ID: W4417133248