2001/02/07 by V. Luridiana, M. Peimbert · 2 citations
Physics and Astronomy · #Astrophysics #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gaussian #Nebula #Photoionization #Physics #Star formation #Stars #Statistical physics #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/320962
33 pages (LaTeX), 3 .eps figures. to be published in ApJ, May 2001
arxiv created 2001/02/07 · openalex publication_date 2001/06/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We compute photoionization models for the giant extragalactic H II region NGC 5461, and compare their predictions to several observational constraints. Since we aim at reproducing not only the global properties of the region, but its local structure also, the models are constrained to reproduce the observed density profile, and our analysis takes into consideration the bias introduced by the shapes and sizes of the slits used by different observers. We find that an asymmetric nebula with a gaussian density distribution, powered by a young burst of 3.1 Myr, satisfactorily reproduces most of the constraints, and that the star-formation efficiency inferred from the model agrees with current estimates. Our results strongly depend on the assumed density law, since constant density models overestimate the hardness of the ionizing field, affecting the deduced properties of the central stellar cluster. We illustrate the features of our best model, and discuss the possible sources of errors and uncertainties affecting the outcome of this type of studies.