Galactic Structure and Stellar Populations
نویسنده
چکیده
The Milky Way Galaxy offers a unique opportunity for testing theories of galaxy formation and evolution. I discuss how large surveys, both photometric and spectroscopic, of Galactic stars are the keystones of investigations into such fundamental problems as the merging history – and future – of the Galaxy.
منابع مشابه
Stellar Populations in the Central Galaxies of Fossil Groups
It is inferred from the symmetrical and luminous X-ray emission of fossil groups that they are mature, relaxed galaxy systems. Cosmological simulations and observations focusing on their dark halo and inter-galactic medium properties confirm their early formation. Recent photometric observations suggest that, unlike the majority of non-fossil brightest group galaxies (BGGs), the central early-t...
متن کاملThe effect of variation of stellar dispersion velocities by the galactic latitude in interpreting gravitational microlensing observations
Our galaxy is a spiral galaxy and its stars are mostly in a thin disk and rotate around the galactic center. The vertical component of the dispersion velocity of stars is a function of the galactic latitude and decreases with increasing it. In the galactic Besancon model, this dependence is ignored and they just consider the dependence of dispersion velocity on the stellar age. Becanson model i...
متن کاملPulsating red giant and supergiant stars in the Local Group dwarf galaxy Andromeda I
We have conducted an optical long-term monitoring survey of the majority of dwarf galaxies in the Local Group, with the Isaac Newton Telescope (INT), to identify the long period variable (LPV) stars. LPV stars vary on timescales of months to years, and reach the largest amplitudes of their brightness variations at optical wavelengths, due to the changing temperature. They trace stellar populati...
متن کاملIdentification of Stellar Population in Galactic Spectra Using the Hierarchical Desicion Ensemble
In order to understand the process of formation and evolution of a galaxy, it is very important to identify the ages of stellar populations that make it up. The main contribution of this work is an efficient machine learning method, insensitive to emission lines and robust in the presence of noise, to determine the age of stellar populations in observational galactic spectra. It is a novel meth...
متن کاملObservations of multiple populations in star clusters
An increasing number of photometric observations of multiple stellar populations in Galactic globular clusters is seriously challenging the paradigm of GCs hosting single, simple stellar populations. These multiple populations manifest themselves in a split of different evolutionary sequences as observed in the cluster color-magnitude diagrams. Multiple stellar populations have been identified ...
متن کامل