%0 Journal Article
%T COMMENTARY ON "ELECTRON TEMPERATURES AND DENSITIES IN PNE" BY PEIMBERT (1971)
%A Miriam Peu00F1a
%J Revista mexicana de astronom¨ªa y astrof¨ªsica
%D 2011
%I Universidad Nacional Aut¨®noma de M¨¦xico
%X The discrepancies in electron temperatures in photoionized nebulae, as derived from collisionally excited lines and the hydrogen Balmer jump are presented. M. Peimbert in 1971, BOTT, 6, 36, 29 was the first in determining such discrepancies for a sample of PNe. Many authors have confirmed this result in many different samples of PNe. The discrepancies in electron temperatures are related to the discrepancies in the abundances of heavy element when derived from optical recombination lines, ORLs, or from collisionally excited lines, CELs. ORLs abundances are always larger than CELs abundances. For PNe the ratios between both abundances are in the range 1.2 3.2, but much larger values have been found in some PNe. The two main proposals trying to explain these discrepancies are: (a) the presence of temperature fluctuations in the plasma or (b) the presence of small H-deficient low-temperature inclusions, where most of the emission of ORLs would be produced. None of these proposals have been clearly demonstrated so far.
%U http://www.redalyc.org/articulo.oa?id=57120832023