相关论文: Star Formation Histories of Local Group Dwarf Gala…
40 galaxies are currently known as, or suspected to be Local Group members within a radius of 1.8 Mpc. 37 of these galaxies are dwarf galaxies with M_B > -18.5 mag. I present a compilation of the star formation histories of dwarf…
The star formation histories of Local Group galaxies are summarized. The three large spirals are discussed individually, whereas the discussion of the Local Group dwarfs concentrates on differences and commonalities. While Local Group…
The aim of this paper is to cast light on the formation and evolution of elliptical galaxies by means of N-body/hydro-dynamical simulations that include star formation, feed-back and chemical evolution. Particular attention is paid to the…
The dwarf galaxies of the Local Group can be separated in three morphological groups: irregular, elliptical and spheroidal. As in the large galaxy clusters, there seems to be a morphology-position relationship: irregular galaxies are…
We present uniformly measured star formation histories (SFHs) of 40 Local Group dwarf galaxies based on color-magnitude diagram (CMD) analysis from archival Hubble Space Telescope imaging. We demonstrate that accurate SFHs can be recovered…
Properties of nearby dwarf galaxies are briefly discussed. Dwarf galaxies vary widely in their star formation histories, the ages of their subpopulations, and in their enrichment history. Furthermore, many dwarf galaxies show evidence for…
The characteristics and properties of the stellar populations and evolutionary histories of Local Group galaxies are summarized and compared to predictions of cosmological models. No clear signature of the re-ionization epoch is observed;…
We analyse the properties of three unusual dwarf galaxies in the Centaurus A group discovered with the HIPASS survey. From their optical morphology they appear to be low surface brightness dwarf spheroidals, yet they are gas-rich…
The star formation histories (SFHs) of galaxies provide valuable insights into galaxy evolution and stellar physics. Understanding the SFHs enables the study of chemical enrichment of galaxies, star formation triggered by interactions, and…
Dwarf galaxies in the Local Group (LG) represent a distinct as well as diverse family of tracers of the earliest phases of galaxy assembly and the processing resulting from galactic harassment. Their stellar populations can be resolved and…
It is an obvious statement that all the galaxies we see today in and around our Local Group have been forming and evolving for a significant fraction of the age of the Universe. It is not a great leap of logic to further state that the…
We present the star formation histories (SFHs) of early-type dwarf galaxies, dSphs and dEs, in the local universe within z=0.01. The SFHs of early-type dwarf galaxies are characterized by pre-enriched, metal-poor old stellar populations,…
More than half of all stars in the local Universe are found in massive spheroidal galaxies, which are characterized by old stellar populations with little or no current star formation. In present models, such galaxies appear rather late as…
We compare the properties of dwarf galaxies in the Local Group with the simulated galaxies formed before reionization in a cosmological simulation of unprecedented spatial and mass resolution,including radiative feedback effects. We find…
The star formation histories of Local Group (LG) dwarf galaxies and more distant potential LG members are reviewed. Problems in defining the spatial extent of the LG and membership are briefly discussed. The morphological types found in the…
In the Local Group there are three main types of dwarf galaxies: Dwarf Irregulars, Dwarf Spheroidals, and Dwarf Ellipticals. Intermediate/transitional types are present as well. This contribution reviews the idea that the present day…
Within the Local Universe galaxies can be studied in great detail star by star, and here we review the results of quantitative studies in nearby dwarf galaxies. The Color-Magnitude Diagram synthesis method is well established as the most…
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…
The current evidence about the age of stellar populations in elliptical galaxies is reviewed. The case for the bulk of stars in galactic spheroids (ellipticals and bulges) having formed at high redshift (z>~3) is now compelling, both for…
The unprecedented quality of recent colour-magnitude diagrams of resolved stellar populations in nearby galaxies requires state-of-the-art techniques to infer the star formation histories which gave rise to the observed distributions. We…