scholarly journals The Effects of Binaries on Population Studies

2004 ◽  
Vol 194 ◽  
pp. 85-86
Author(s):  
Dany Vanbeveren
Keyword(s):  
Star Formation ◽  
Chemical Evolution ◽  
Population Studies ◽  
Stellar Populations ◽  
Spectral Evolution ◽  
Evolution Of Galaxies ◽  
Starburst Regions

AbstractWe give an overview of the work that has been done in Brussels since 1997 on various aspects of population studies and the effects of binaries: stellar populations and supernova rates in regions where star formation is continuous and in starbursts, the expected spectral evolution of starburst regions, the chemical evolution of galaxies.

scholarly journals Stellar Populations in High-z Galaxy Mergers

1999 ◽  
Vol 186 ◽  
pp. 202-202
Author(s):  
Yasuhiro Shioya ◽  
Kenji Bekki
Keyword(s):  
Star Formation ◽  
Chemical Evolution ◽  
Stellar Populations ◽  
Star Formation History ◽  
Galaxy Mergers ◽  
Formation History ◽  
Self Consistent ◽  
Consistent Manner ◽  
History Of ◽  
The Difference

We investigate the nature of stellar populations of major galaxy mergers between late-type spirals considerably abundant in interstellar medium by performing numerical simulations designed to solve both the dynamical and chemical evolution in a self-consistent manner. We particularly consider that the star formation history of galaxy mergers is a crucial determinant for the nature of stellar populations of merger remnants, and therefore investigate how the difference in star formation history between galaxy mergers affects the chemical evolution of galaxy mergers.

scholarly journals Limits on the Missing Mass in Dark Stellar Remnants

1987 ◽  
Vol 117 ◽  
pp. 411-411
Author(s):  
Janet E. Jones ◽  
Philip Mellor ◽  
Jesper Storm
Keyword(s):  
Star Formation ◽  
Chemical Evolution ◽  
Initial Conditions ◽  
Computer Models ◽  
Elliptical Galaxies ◽  
Evolutionary Processes ◽  
Disk System ◽  
Missing Mass ◽  
Evolution Of Galaxies ◽  
The Galaxy

A set of comprehensive computer models for the chemical evolution of galaxies have been used to determine the limits on the amount of mass that could exist in the form of dark stellar remnants deriving from normal stellar evolutionary processes. In these models, the instantaneous recycling approximation is not assumed: stars are binned into 10 mass intervals, with different lifetimes, yields and remnant masses. The models were run using many different values for the IMF (including non-Salpeter and varying IMFs), star formation rates, yields, remnant masses, gas infall and outflow rates, primordial metalliciy and initial conditions. The Galaxy is described by a two-zone halo-disk system, where gas from the halo falls onto the disk. Elliptical galaxies are described by single-zone models.

scholarly journals The Chemical Evolution of the Galactic Halo and Disk

1987 ◽  
Vol 115 ◽  
pp. 701-703
Author(s):  
Federico Ferrini ◽  
Francesco Palla ◽  
Steven N. Shore
Keyword(s):  
Star Formation ◽  
Chemical Evolution ◽  
Galactic Halo ◽  
Stellar Populations ◽  
Galactic Evolution ◽  
Formation Model ◽  
Present Epoch ◽  
The Galaxy ◽  
Metal Abundance ◽  
History Of

The history of star formation in our galaxy is written in the metal abundance distributions of the stellar populations. Any star formation model is constrained by two facts. First, there was a period in the early stages of galactic evolution during which the metallicity of the gas out of which stars were being formed was significantly lower than the present epoch. Second, there is a paucity of extremely metal deficient stars in the disk of the galaxy.

scholarly journals Summary

1983 ◽  
Vol 6 ◽  
pp. 201-202
Author(s):  
Kenneth C. Freeman
Keyword(s):  
Star Formation ◽  
Chemical Evolution ◽  
Current Knowledge ◽  
Galactic Bulge ◽  
Spiral Arms ◽  
Evolution Of Galaxies ◽  
The Imf

The old populations of galaxies are particularly vital for understanding the formation and chemical evolution of galaxies. As in any field, ideas come and go, and today’s discussion has given us a valuable assessment of current knowledge and thinking on many topics.The problems of star formation and the IMF are basic to many aspects of work on old populations. The discussion included some interesting ideas on star formation, and a useful warning that there are probably different modes of star formation which may give different IMFs: for example the mode of star formation that is widely studied now (in spiral arms) is probably different to the mode of star formation that was active in forming the stars of the galactic bulge.

scholarly journals The evolution of massive stars

1997 ◽  
Vol 189 ◽  
pp. 313-322 ◽  
Author(s):  
A. Maeder
Keyword(s):  
Star Formation ◽  
Uv Radiation ◽  
Chemical Evolution ◽  
Interstellar Dust ◽  
Galactic Center ◽  
Massive Stars ◽  
Galactic Nuclei ◽  
Proper Understanding ◽  
Evolution Of Galaxies ◽  
Distant Galaxies

Massive stars are the crossroads of many important astrophysical problems and thus a proper understanding of their evolution is very needed. They are the main sources of UV radiation, by heating the interstellar dust they produce the far-IR luminosities of galaxies. They are the precursors of Supernovae and also the main sources of nucleosynthesis. They are visible in distant galaxies and the recent observations of starbursts have shown their major role in the spectral and chemical evolution of galaxies. They begin to be observed in the galactic center and in regions of star formation around galactic nuclei.

scholarly journals The origin of stellar populations in the Galactic bulge from chemical abundances

2019 ◽  
Vol 487 (4) ◽  
pp. 5363-5371 ◽  
Author(s):  
F Matteucci ◽  
V Grisoni ◽  
E Spitoni ◽  
A Zulianello ◽  
A Rojas-Arriagada ◽  
...  
Keyword(s):  
Star Formation ◽  
Chemical Evolution ◽  
Formation Rate ◽  
Age Distribution ◽  
Stellar Populations ◽  
Distribution Functions ◽  
Galactic Bulge ◽  
Chemical Abundances ◽  
Abundance Pattern ◽  
Secular Evolution

ABSTRACT In this work, we study the formation and chemical evolution of the Galactic bulge with particular focus on the abundance pattern ([Mg/Fe] versus [Fe/H]), metallicity, and age distribution functions. We consider detailed chemical evolution models for the Galactic bulge and inner disc, with the aim of shedding light on the connection between these components and the origin of bulge stars. In particular, we first present a model assuming a fast and intense star formation, with the majority of bulge stars forming on a time-scale less than 1 Gyr. Then we analyse the possibility of two distinct stellar populations in the bulge, as suggested by Gaia-ESO and APOGEE data. These two populations, one metal poor and the other metal rich, can have had two different origins: (i) the metal rich formed after a stop of ∼250 Myr in the star formation rate of the bulge or (ii) the metal-rich population is made of stars formed in the inner disc and brought into the bulge by the early secular evolution of the bar. We also examine the case of multiple starbursts in the bulge with consequent formation of multiple populations, as suggested by studies of microlensed stars. After comparing model results and observations, we suggest that the most likely scenario is that there are two main stellar populations, both made mainly by old stars (>10 Gyr), with the metal-rich and younger one formed from inner thin disc stars, in agreement with kinematical arguments. However, on the basis of dynamical simulations, we cannot completely exclude that the second population formed after a stop in the star formation during the bulge evolution, so that all the stars formed in situ.

scholarly journals The Effects of Galactic Winds on the Chemical Evolution of Baryons

2009 ◽  
Vol 5 (S262) ◽  
pp. 325-326
Author(s):  
María E. De Rossi ◽  
Patricia B. Tissera
Keyword(s):  
Star Formation ◽  
Numerical Simulations ◽  
Chemical Evolution ◽  
Intergalactic Medium ◽  
Origin And Evolution ◽  
Chemical Enrichment ◽  
Evolution Of Galaxies ◽  
Galactic Winds

AbstractDuring the last decade, the development of more sophisticated surveys allows the exploration of the chemical enrichment of galaxies and their environment at different cosmic times. In this context, it has been suggested that galactic winds play a fundamental role in the regulation of the star formation and the transportation of metals outside the galaxies. In this work, we study the influence of Supernovae winds in the chemical evolution of galaxies and the intergalactic medium by employing cosmological numerical simulations within a hierarchical Universe. We focus on the origin and evolution of the mass-metallicity relation (MZR).

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