相关论文: Dark Matter and the Chemical Evolution of Irregula…
Photometric properties of stellar populations that evolve according to chemical evolution models developed by Carigi, Colin, & Peimbert (1999) and Carigi & Peimbert (2001) are explored. Models explain the oxygen abundance and gas mass…
Dwarf irregular and blue compact galaxies are very interesting objects since they are relatively simple and unevolved. We present new models for the chemical evolution of these galaxies by assuming different regimes of star formation…
Dwarf irregular galaxies appear to have undergone very slow chemical evolution since they have low nebular abundances, but have had ongoing star formation over the past 15 Gyr. They are too distant for red giant abundance analyses to…
Blue Compact Dwarf and Dwarf Irregular galaxies are generally believed to be unevolved objects, due to their blue colors, compact appearance and large gas fractions. Many of these objects show an ongoing intense burst of star formation or…
A chemical evolution model following the evolution of the abundances of H, He, C, N, O and Fe for dwarf irregular and blue compact galaxies is presented. This model takes into account detailed nucleosynthesis and computes in detail the…
The state-of-the-art of chemical evolution models for Irregular and Blue Compact galaxies is reviewed. The resulting scenarios for the initial mass function, the regime of star formation and the efficiency of gas outflows are described: The…
A numerical double burst model of the chemical evolution of gas-rich dwarf galaxies has been developed. The model is fitted to a sample of N/O, O/H, Y and gas fraction observations, where N/O and O/H are the relative abundances by number of…
Blue Compact Dwarf and Dwarf Irregular galaxies are generally believed to be unevolved objects, due to their blue colors, compact appearance and large gas fractions. Many of these objects show an ongoing intense burst of star formation or…
Dwarf irregular galaxies are relatively simple unevolved objects where it is easy to test models of galactic chemical evolution. We attempt to determine the star formation and gas accretion history of IC10, a local dwarf irregular for which…
We discuss the chemical evolution of metal poor galaxies and conclude that their oxygen deficiency is not due to: the production of black holes by massive stars or a varying slope of the Initial Mass Function, IMF, at the high-mass end. A…
Initial conditions are set by Big bang nucleosynthesis from which we know that 90 per cent of baryons are dark and have essentially unknown chemical composition. In our own Galaxy, there are many clues from individual stars in different…
I review the current data on abundances in irregular galaxies, with special emphasis on recent results on C/O and Si/O from observations with the Hubble Space Telescope. The abundance data for He, C, N, and O in irregular galaxies is…
(Abridged.) We present one-zone chemical evolution models for two dwarf starburst galaxies, NGC 1705 and NGC 1569. Using information about the past star formation history and initial mass function of the systems previously obtained from…
We compute chemical evolution models to constrain the mode and the history of star formation in starburst galaxies as a whole, i.e. over a large range of mass and metallicity. To this end, we investigate the origin of the dispersion…
We present long slit optical spectroscopy of 67 HII regions in 21 dwarf irregular galaxies to investigate the enrichment of oxygen, nitrogen, neon, sulfur, and argon in low mass galaxies. Oxygen abundances are obtained via direct detection…
In order to recognize environmental effects on the evolution of dwarf galaxies in clusters of galaxies, it is first necessary to quantify the properties of objects which have evolved in relative isolation. With oxygen abundance as the gauge…
We investigate the chemical evolution of odd-numbered elements such as sodium (Na) and aluminum (Al) during the early epochs of the Galactic halo with the use of a model that reproduces the observed box-shaped distribution of extremely…
The evolution of irregular galaxies is examined from two points of view: on the one hand, models of galactic chemical evolution have been computed and their predictions compared with the corresponding observational data on the element…
By means of chemical evolution models for galaxies of different morphological type, we have performed a detailed study of the evolution of the cosmic dust properties in different environments: the solar neighbourhood, elliptical galaxies…
Irregular (Irr) galaxies are gas-rich objects with recent or ongoing star formation. In absence of spiral density waves, star formation occurs largely stochastically. The scattered star-forming regions tend to be long-lived and migrate…