相关论文: Bulges
Adopting a single-zone framework, with accretion of primordial gas on a free-fall timescale, the chemical evolution of the Galactic bulge is calculated, assuming (i) a corresponding rapid timescale for star formation, and (ii) an initial…
Recent work has produced a wealth of data concerning the chemical evolution of the galactic bulge, both for stars and nebulae. Present theoretical models generally adopt a limited range of such constraints, frequently using a single…
We show our results from the application of the Multiphase chemical evolution model to a set of Bulges of spiral galaxies
We compute the chemical evolution of the Galactic bulge in the context of an inside-out model for the formation of the Milky Way. The model contains updated stellar yields from massive stars. The main purpose of the paper is to compare the…
We present results for the chemical evolution of the Galactic bulge in the context of an inside-out formation model of the Galaxy. A supernova-driven wind was also included in analogy with elliptical galaxies. New observations of chemical…
We review current knowledge on the structure, properties and evolution of galactic bulges, considering particularly common preconceptions in the light of recent observational results.
Electron temperatures, densities, ionic and elemental abundances of helium, nitrogen, oxygen, argon, sulfur and neon were derived for a sample of bulge planetary nebulae, representative of its intermediate mass population. Using these…
Galactic bulges are central to understanding galaxy formation and evolution. Here we report on recent studies using micro-lensing events to obtain spectra of high resolution and moderately high signal-to-noise ratios of dwarf stars in the…
This is the first paper presenting our long-term project aimed at studying the nature of bulges through the analysis of their stellar population gradients. We present deep spectroscopic observations along the minor axis and the data…
This review summarizes the properties of the stellar population in bulges as observed in nearby or distant spiral galaxies. It gives a particular emphasis to the comparison with elliptical galaxies, when possible. The criteria of sample…
Until recently our knowledge of the Galactic Bulge stellar populations was based on the study of a few low extinction windows. Large photometric and spectroscopic surveys are now underway to map large areas of the bulge. They probe several…
Bulges are of different types, morphologies and kinematics, from pseudo-bulges, close to disk properties (Sersic index, rotation fraction, flatenning), to classical de Vaucouleurs bulges, close to elliptical galaxies. Secular evolution and…
In this work, we study the formation and chemical evolution of the Galactic bulge with particular focus on the abundance pattern ([Mg/Fe] vs. [Fe/H]), metallicity and age distribution functions. We consider detailed chemical evolution…
Due to its proximity, the stellar populations of the Galactic bulge (GB) can be resolved and can be studied in detail. This allows tracing the bulge metallicity distribution function (MDF) for different spatial regions within the bulge,…
The chemical evolution of the Galactic bulge is treated here in the context of an inside-out model for the Galaxy formation. We assume that this central region evolved even faster than the Galactic halo and test the effect of changing the…
The role of planetary nebulae as probes for the galactic chemical evolution is reviewed. Their abundances throughout the Galaxy are discussed for key elements, in particular oxygen and other alpha elements. The abundance distribution…
The details of bulge formation via collapse, mergers, secular processes or their interplay remain unresolved. To start answering this question and quantify the importance of distinct mechanisms, we mapped a sample of three galactic bulges…
A historical review of our understanding of bulges is first presented, highlighting similarities and differences between bulges and ellipticals. Then, some topics of current interest are reviewed, bypassing stellar population questions and…
We discuss the integrated properties of the stellar population in bulges along the Hubble sequence and new HST data for individual stars in the bulge of M31.
It is an observational fact that bulges of spiral galaxies contain a high fraction of old and metal-rich stars. Following this observational fact, we have investigated colors of 21 bulges hosted by a selected sample of high surface…