Open AccessThe chemical evolution of gas‐rich dwarf galaxies
Author(s) -
Larsen T. I.,
SommerLarsen J.,
Pagel B. E. J.
Publication year - 2001
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2001.04142.x
Subject(s) - physics , astrophysics , dwarf galaxy , supernova , ejecta , galaxy , chemical evolution , dwarf spheroidal galaxy , stellar evolution , star formation , mixing (physics) , stars , interacting galaxy , quantum mechanics
In an effort to understand the evolution of N, O and He abundances in gas‐rich dwarf galaxies, we investigate the dispersion and mixing of supernova ejecta in relation to H ii region evolution and develop a numerical model of chemical evolution based on a double‐bursting mode of star formation (with an interval of the order of 3×10 7 yr between bursts of a pair) which has been designed to account for the existence of significant scatter in the N/O–O/H relation. The dependence of the abundances on gas fraction is explored on the basis of this and similar models, in combination with various hypotheses concerning inflow and selective and non‐selective outflow. The gas fractions are uncertain within wide limits for blue compact galaxies, but are more well defined for some dwarf irregulars. Selective winds do not give a good fit to N/O, while closed models and models with non‐selective winds with or without inflow are all found to be viable.