相关论文: Euler, Hipparcos and the five dwarfs : Reconstruct…
The evolution of the star formation rate in the Galaxy is one of the key ingredients quantifying the formation and determining the chemical and luminosity evolution of galaxies. Many complementary methods exist to infer the star formation…
This paper develops a method for obtaining the star formation histories of a mixed, resolved population through the use of color-magnitude diagrams (CMDs). The method provides insight into the local star formation rate, analyzing the…
We use data from the Hipparcos catalogue to construct colour-magnitude diagrams for the solar neighbourhood, which are then treated using advanced Bayesian analysis techniques to derive the star formation history, $SFR(t)$, of this region…
This thesis develops a method for obtaining the star formation histories of a mixed, resolved population through the use of color-magnitude diagrams (CMDs). The method is applied to the derivation of the local star formation rate, modeling…
We address the question of the occurrence of star formation bursts in the solar neighbourhood by using the metallicity distribution of the G dwarfs. We present a method to recover the star formation history using simultaneously the…
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…
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 report preliminary results of a project to homogeneously measure star formation histories for the majority of Local Group dwarf galaxies, based on archival WFPC2 observations. For the dwarf spheroidal and elliptical galaxies, we find…
If we are to develop a comprehensive and predictive theory of galaxy formation and evolution, it is essential that we obtain an accurate assessment of how and when galaxies assemble their stellar populations, and how this assembly varies…
We use recent HST colour-magnitude diagrams of the resolved stellar populations of a sample of local dSph galaxies (Carina, LeoI, LeoII, Ursa Minor and Draco) to infer the star formation histories of these systems, $SFR(t)$. Applying a new…
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…
The paucity of observed dwarf galaxies in the Local Group relative to the abundance of predicted dark matter halos remains one of the greatest puzzles of the LCDM paradigm. Solving this puzzle now requires not only matching the numbers of…
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 history in the solar neighbourhood is inferred comparing a sample of field stars from the Hipparcos Catalog with synthetic CMDs. We considered separately the main sequence and the red giant region of the HR diagram. The…
The Gaia DR2 catalog is the best source of stellar astrometric and photometric data available today. The history of the Milky Way galaxy is written in stone in this data set. Parallaxes and photometry tell us where the stars are today, when…
If we are to develop a comprehensive and predictive theory of galaxy formation and evolution, it is essential that we obtain an accurate assessment of how and when galaxies assemble their stellar populations, and how this assembly varies…
A volume limited and absolute magnitude limited sample of A-F type dwarfs within 125 parsecs of the Sun is searched for inhomogeneities in the density- velocity space, expecting signatures of the cluster evaporation, phase mixing and…
What can we learn from the somewhat arduous study of old stellar populations in nearby galaxies? Unless the nearby universe is subtly anomalous, it should contain a relatively normal selection of galaxies whose histories are representative…
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…
We present a new method to derive 2D star formation histories in dwarf irregular galaxies. Based on multicolor stellar photometry data we have found that in the Leo A galaxy during the last $\sim$400 Myr star formation was propagating…