2006/04/01 by M. Peimbert, Manuel Peimbert, Antonio Peimbert · 18 citations
Physics and Astronomy · #Abundance (ecology) #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Astrophysics and Star Formation Studies #Atomic physics #Balmer series #Biology #Chemical evolution #Ecology #Emission spectrum #Excited state #Galaxy #Homogeneous #Ion #Ionization #Photoionization #Physics #Planetary nebula #Spectral line #Stars #Stellar, planetary, and galactic studies #Thermodynamics #astro-ph
paper · pdf · doi:10.1017/s1743921306003012
published in Proceedings of the International Astronomical Union 2(S234), 227-234 (Cambridge University Press) · 8 pages, invited review to appear in Proc. IAU Symp. 234, Planetary Nebulae in Our Galaxy and Beyond (3-7 Apr 2006), eds. M.J. Barlow & R.H. Mendez (Cambridge Univ. Press)
openalex publication_date 2006/04/01 · arxiv created 2006/05/23 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In this review we present a brief discussion on the observational evidence in favor of the presence of temperature variations, and conclude that many planetary nebulae show spatial temperature variations that are larger than those predicted by 1D static chemically homogeneous photoionization models. To determine accurate chemical abundances it is necessary to know the cause of these temperature variations and several possibilities are discussed. The importance of this problem is paramount to test the models of stellar evolution of low and intermediate mass stars and of the chemical evolution of galaxies. We conclude that the proper abundances for chemically homogeneous PNe are those derived from recombination lines, while for the two-abundance nebular model the proper heavy element abundances relative to hydrogen are those derived from visual and UV collisionally excited lines adopting the t2 values derived from Te ([O III]) and Te (Balmer).