Stellar population synthesis of galaxies with chemical evolution model

2019 ◽  
Vol 15 (S341) ◽  
pp. 147-151
Author(s):  
Shiyin Shen ◽  
Jun Yin
Keyword(s):  
Chemical Evolution ◽  
Stellar Population ◽  
Local Group ◽  
Evolution Model ◽  
Star Formation History ◽  
Population Synthesis ◽  
Formation History ◽  
Fitting Algorithm ◽  
Stellar Population Synthesis ◽  
Chemical Evolution Model

AbstractThe derivation of accurate stellar populations of galaxies is a non-trivial task because of the well-known age-metallicity degeneracy. We aim to break this degeneracy by invoking a chemical evolution model (CEM) for isolated disk galaxy, where its metallicity enrichment history (MEH) is modelled to be tightly linked to its star formation history (SFH). Our CEM has been successfully tested on several local group dwarf galaxies whose SFHs and MEHs have been both independently measured from deep colour-magnitude diagrams of individual stars. By introducing the CEM into the stellar population fitting algorithm as a prior, we expect that the SFH of galaxies could be better constrained.

A unified construction of stellar evolution and chemical evolution models for the multiple populations in globular clusters

2019 ◽  
Vol 14 (S351) ◽  
pp. 302-304
Author(s):  
Sohee Jang ◽  
Jenny J. Kim ◽  
Young-Wook Lee
Keyword(s):  
Star Formation ◽  
Chemical Evolution ◽  
Globular Clusters ◽  
Evolution Model ◽  
Star Formation History ◽  
Multiple Populations ◽  
Rr Lyrae ◽  
Formation History ◽  
Type Ab ◽  
Chemical Evolution Model

AbstractRecent investigations of multiple stellar populations in globular clusters (GCs) suggest that the horizontal-branch (HB) morphology and mean period of type ab RR Lyrae variables are mostly sensitive to helium abundance, while the star formation timescale has the greatest effect on our chemical evolution model constructed to reproduce the Na-O anti-correlation of GCs. Therefore, by combining the results from synthetic HB model with those from chemical evolution model, we could put better constraints on star formation history and chemical evolution in GCs with multiple populations. From such efforts made for four GCs, M4, M5, M15, and M80, we find that consistent results can be obtained from these two independent models.

scholarly journals A Comparison of Chemical Evolution between the Milky Way and M31 Galaxy

2006 ◽  
Vol 2 (S235) ◽  
pp. 313-313
Author(s):  
J. Yin ◽  
J.L. Hou ◽  
R.X. Chang ◽  
S. Boissier ◽  
N. Prantzos
Keyword(s):  
Star Formation ◽  
Chemical Evolution ◽  
Milky Way ◽  
Local Group ◽  
Spiral Galaxies ◽  
Star Formation History ◽  
Milky Way Galaxy ◽  
Andromeda Galaxy ◽  
Formation History ◽  
Formation And Evolution

Andromeda galaxy (M31,NGC224) is the biggest spiral in the Local Group. By studying the star formation history(SFH) and chemical evolution of M31, and comparing with the Milky Way Galaxy, we are able to understand more about the formation and evolution of spiral galaxies.

scholarly journals The Massive stellar Population at the Galactic Center

2016 ◽  
Vol 12 (S329) ◽  
pp. 287-291
Author(s):  
Francisco Najarro ◽  
Diego de la Fuente ◽  
Tom R. Geballe ◽  
Don F. Figer ◽  
D. John Hillier
Keyword(s):  
Star Formation ◽  
Massive Star ◽  
Stellar Population ◽  
Milky Way ◽  
Local Group ◽  
Galactic Center ◽  
Spectroscopic Studies ◽  
Star Formation History ◽  
Stellar Content ◽  
Formation History

AbstractWe present results from our ongoing infrared spectroscopic studies of the massive stellar content at the Center of the Milky Way. This region hosts a large number of apparently isolated massive stars as well as three of the most massive resolved young clusters in the Local Group. Our survey seeks to infer the presence of a possible top-heavy recent star formation history and to test massive star formation channels: clusters vs isolation.

scholarly journals Stellar population synthesis: Application To Galactic Bulges

1993 ◽  
Vol 153 ◽  
pp. 133-150
Author(s):  
N. Arimoto
Keyword(s):  
Observational Data ◽  
Stellar Population ◽  
Stellar Populations ◽  
Population Synthesis ◽  
Firm Conclusion ◽  
Formation History ◽  
Stellar Population Synthesis ◽  
Central Regions ◽  
History Of ◽  
Metallicity Distribution

The stellar populations give traces of the formation history of the bulges. The metallicity distribution of K-giants in the Galactic bulge resembles to that of the giant ellipticals. There seems to be no conspicuous colour-magnitude relation intrinsic to the bulges. This can be explained if the bulges formed by the dissipative collapse of central regions of proto-galaxies followed by the supernova-driven bulge wind which was induced later than the dwarf ellipticals of the similar mass (the biased wind). Unfortunately, the observational data available at present of stellar populations of the bulges are not yet sufficient to get a firm conclusion on the origin of the bulges.

scholarly journals Stellar Populations in Mixed Pairs of Galaxies

1995 ◽  
Vol 164 ◽  
pp. 434-434 ◽  
Author(s):  
D.F. De Mello ◽  
W.C. Keel ◽  
J.W. Sulentic ◽  
R. Rampazzo
Keyword(s):  
Star Formation ◽  
Stellar Population ◽  
Elliptical Galaxy ◽  
Star Formation History ◽  
Population Synthesis ◽  
Early Type ◽  
Stellar Content ◽  
Stellar Population Synthesis ◽  
History Of ◽  
Early Type Galaxy

The interpration of the interaction in galaxies is simplified in mixed pairs (E+S) because most or all of the cold gas can be traced to an origin in a single galaxy (S). We used spectroscopy, imaging, far–IR, and stellar population synthesis to study the stellar content and history of star formation in the nuclear region of the early–type galaxy in the mixed pair AM0327–285. We used the procedure for stellar population synthesis developed by Bica (1988) to estimate the star-formation history of the nucleus of the elliptical galaxy. The method uses a library of star clusters, and estimates the chemical evolution in a test population with two parameters: age and metallicity; no assumptions on gravity or details of stellar evolution are necessary, and the IMF is implicit in the cluster spectra. The procedure allows one to both determine the chemical enrichment and date successive generations of star formation. The result indicates that the dominant population is old and metal–rich ([Z/Z]⊙=0.3), while ~ 10% of the flux at 5870 Å arises from a young stellar population (age ≤ 5 × 108 yr), confirming that this early-type galaxy had recent star formation as suggested also by photometry and far–IR data (de Mello et al 1994). This age is close to several estimates of the characteristic timescale of the interaction, suggesting that the mass influx associated with this star formation occurred as a result of an earlier phase of the interaction and not as a result of the present geometry of the pair.

scholarly journals Inverse population synthesis using a dynamical basis

2009 ◽  
Vol 5 (S262) ◽  
pp. 388-389
Author(s):  
Juan Mateu ◽  
Gladis Magris ◽  
Gustavo Bruzual
Keyword(s):  
Star Formation ◽  
High Resolution ◽  
Stellar Population ◽  
Star Formation History ◽  
Population Synthesis ◽  
Synthesis Algorithm ◽  
Inverse Population ◽  
Synthetic Spectra ◽  
Formation History ◽  
Good Agreement

AbstractWe introduce a new inverse population synthesis algorithm (DINBAS3D) which aims to recover the star formation and metallicity histories from galactic spectra. We investigate the use of a dynamical basis of three simple stellar population spectra that is specific for each galaxy. Our goal is to recover a robust star formation history that minimizes degeneracy effects which are very common in high resolution histories methods. In this work, we detail the method and present our findings when we apply DINBAS3D to synthetic spectra with known parameters, we compare our results with similar methods and find good agreement between them.

scholarly journals Stellar and dust SED modelling of the Whirlpool interacting galaxy system

2011 ◽  
Vol 7 (S284) ◽  
pp. 107-111
Author(s):  
Erin Mentuch ◽  
Christine Wilson
Keyword(s):  
Star Formation ◽  
Dust Emission ◽  
Star Formation History ◽  
Starburst Galaxy ◽  
Population Synthesis ◽  
Star Formation Activity ◽  
Formation History ◽  
Stellar Population Synthesis ◽  
Multi Wavelength ◽  
Emission Models

AbstractSome 300-500 Myr ago, the Whirlpool galaxy (NGC 5194/M51a) and its nearby post-starburst galaxy neighbour, NGC 5195/M51b closely interacted, resulting in significant changes to their star formation activity. Both galaxies display colors indicative of enhanced star formation during closest passage, but since then, star formation has ceased in NGC 5195 yet remained ongoing in the spiral NGC 5194. With a wealth of multi-wavelength (0.2–500 μm for this study) observations available, this nearby (10 Mpc) system, whose star formation history is well constrained through optical colors of individual stars and its dynamical history, provides the optimal laboratory to test the relation between dust emission and stellar emission within the fundamental framework of today's stellar population synthesis and dust emission models.

scholarly journals Recovering the ages and metallicities of stars of a complex stellar population system

2008 ◽  
Vol 4 (S258) ◽  
pp. 245-252
Author(s):  
Sebastian L. Hidalgo ◽  
Antonio Aparicio ◽  
Carme Gallart
Keyword(s):  
Star Formation ◽  
Strong Interaction ◽  
Stellar Population ◽  
Local Group ◽  
Dwarf Galaxies ◽  
Star Formation History ◽  
Host Galaxy ◽  
Population System ◽  
Formation History ◽  
Magnitude Diagram

AbstractWe present a new method to solve for the star-formation history (SFH) of a complex stellar population system from the analysis of the color-magnitude diagram (CMD). The SFH is obtained in four steps: i) computing a synthetic CMD, ii) simulating observational effects, iii) parameterization and sampling of the synthetic and observed CMDs, and iv) solving and averaging the solutions. The consistency and stability of the method have been tested using a mock stellar population.The method has been used to solve the SFH of a set of six isolated Local Group dwarf galaxies observed with HST. The main goal is to probe the effects of cosmological processes, such as reionization in the early star formation, or the ability of SNe feedback to remove gas in small halos, in dwarf galaxies free from environmental effects due to the strong interaction with the host galaxy.

scholarly journals Spectrophotometric Population Synthesis of Early Type Galaxies

1996 ◽  
Vol 171 ◽  
pp. 460-460
Author(s):  
A. Vazdekis ◽  
R. Peletier ◽  
E. Casuso ◽  
J. Beckman
Keyword(s):  
Absorption Line ◽  
Chemical Evolution ◽  
Stellar Population ◽  
Stellar Populations ◽  
Population Synthesis ◽  
Early Type ◽  
Evolutionary Scheme ◽  
Stellar Population Synthesis

We have developed a new stellar population synthesis model for calculating colours and absorption line indices in early type galaxies. This model can work either for single-age stellar populations or in an evolutionary scheme following the chemical evolution. The model is based on the isochrones of the Padova group and we have developed our own method of conversion to colours. Details can be found in Vazdekis A., Casuso E., Peletier R. & Beckman J. (submitted, 1995). To test the model we have obtained accurate observations in many colours and line indices of the three standard galaxies: NGC 3379, NGC 4472 and NGC 4594.

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