相关论文: Statistical analysis of stellar evolution

Stars are fossils that retain the history of their host galaxies. Elements heavier than helium are created inside stars and are ejected when they die. From the spatial distribution of elements in galaxies, it is therefore possible to…

The color-magnitude relation (CMR) of early-type galaxies in clusters provides a powerful tool for finding clusters and determining photometric redshifts for clusters using two-filter imaging data. We demonstrate the high accuracy of…

Variations in the photometric parameters of stellar systems as a function of their evolution and the stellar populations comprising them are investigated. A set of seven evolutionary models with an exponential decrease in the star-formation…

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 present unified chemical and spectrophotometric evolutionary synthesis models that allow to describe composite stellar populations in a chemically consistent way. Keeping track of the ISM abundance at birth of each star and using sets of…

The color-magnitude diagrams (CMDs) of intermediate-age star clusters (less than ~ 2 Gyr) are much more complex than those predicted by coeval, nonrotating stellar evolution models. Their observed extended main sequence turnoffs (eMSTOs)…

Stellar ages are critical for understanding the temporal evolution of a galaxy. We calculate the ages of over 6000 red giant branch stars in the Large Magellanic Cloud (LMC) observed with SDSS-IV / APOGEE-S. Ages are derived using…

The color-magnitude diagrams (CMDs) of young star clusters show that, particularly at ultraviolet wavelengths, their upper main sequences (MSs) bifurcate into a sequence comprising the bulk population and a blue periphery. The spatial…

Globular star clusters that formed at the same cosmic time may have evolved rather differently from a dynamical point of view (because that evolution depends on the internal environment) through a variety of processes that tend…

Stellar photometric variability offers a novel probe of the interior structure and evolutionary state of stars. Here we present a census of stellar variability on day to decade timescales across the color-magnitude diagram for 73,000 stars…

N-body + hydrodynamical simulations of the formation and evolution of galaxy groups and clusters in a LambdaCDM cosmology are used in order to follow the building-up of the colour-magnitude relation in two clusters and in 12 groups. We have…

Many aspects of the evolution of stars, and in particular the evolution of binary stars, remain beyond our ability to model them in detail. Instead, we rely on observations to guide our often phenomenological models and pin down uncertain…

Conventionally, CMD analyses of nearby star clusters are based on observations in 2 passbands. They are plagued by considerable degeneracies between age, metallicity, distance (and extinction) that can largely be resolved by including…

In this work, we study the evolution with redshift of the colour-magnitude relation (CMR) of early-type galaxies. This evolution is analyzed through cosmological numerical simulations from z = 2 to z = 0. The preliminary results shown here…

We investigate giant molecular cloud (GMCs) collisions and their ability to induce gravitational instability and thus star formation. This mechanism may be a major driver of star formation activity in galactic disks. We carry out a series…

Giant molecular clouds (GMCs) are the primary reservoirs of cold, star-forming molecular gas in the Milky Way and similar galaxies, and thus any understanding of star formation must encompass a model for GMC formation, evolution, and…

The dissertation presents result from study of Pre-main sequence (PMS) stars that are in the earliest stages of stellar evolution. These young stellar objects are still in the process of formation, and the energy they emit is produced only…

The luminosity function of galaxies is derived from a cosmological hydrodynamic simulation of a Lambda cold dark matter (CDM) universe with the aid of a stellar population synthesis model. At z=0, the resulting B band luminosity function…

We present our new, fully-automated method to detect and measure the ages of star clusters in nearby galaxies, where individual stars can be resolved. The method relies purely on statistical analysis of observations and Monte-Carlo…

Recent radio observations towards nearby galaxies started to map the whole disk and to identify giant molecular clouds (GMCs) even in the regions between galactic spiral structures. Observed variations of GMC mass functions in different…