scholarly journals Mapping the Distribution of Luminous and Dark Matter in Strong Lensing Galaxies

2007 ◽  
Vol 3 (S244) ◽  
pp. 206-215 ◽  
Author(s):  
Ignacio Ferreras ◽  
Prasenjit Saha ◽  
Liliya L. R. Williams ◽  
Scott Burles
Keyword(s):  
Dark Matter ◽  
Gravitational Lensing ◽  
Stellar Population ◽  
Matter Content ◽  
Population Synthesis ◽  
Massive Galaxies ◽  
Optical Images ◽  
Two Samples ◽  
Stellar Population Synthesis ◽  
Strong Lensing

AbstractWe present the distribution of luminous and dark matter in a set of strong lensing (early-type) galaxies. By combining two independent techniques – stellar population synthesis and gravitational lensing – we can compare the baryonic and dark matter content in these galaxies within the regions that can be probed using the images of the lensed background source. Two samples were studied, extracted from the CASTLES and SLACS surveys. The former probes a wider range of redshifts and allows us to explore the mass distribution out to ~ 5Re. The high resolution optical images of the latter (using HST/ACS) are used to show a pixellated map of the ratio between total and baryonic matter. We find dark matter to be absent in the cores of these galaxies, with an increasing contribution at projected radii R ≳ Re. The slopes are roughly compatible with an isothermal slope (better interpreted as an adiabatically contracted NFW profile), but a large scatter in the slope exists among galaxies. There is a trend suggesting most massive galaxies have a higher content of dark matter in the regions probed by this analysis.

scholarly journals Dark matter in massive early-type galaxies: 100 years of the jeans equations

2019 ◽  
pp. 1-21
Author(s):  
S. Samurovic
Keyword(s):  
Dark Matter ◽  
Planetary Nebula ◽  
Stellar Population ◽  
Stellar Dynamics ◽  
Stellar Systems ◽  
Population Synthesis ◽  
Early Type ◽  
Stellar Spectra ◽  
Cluster Data ◽  
Stellar Population Synthesis

In 1919 James Jeans published the book Problems of Cosmogony and Stellar Dynamics in which he summarized his work on dynamics of stellar systems based on his papers published from 1915 onwards. To mark the centenary of this publication we present here one application of his work relevant for contemporary research of galaxies: we analyze the problem of dark matter in massive early-type galaxies (ellipticals and lenticulars) using various available observational data. After discussing the basics of the Jeans equations we study their application on the integrated stellar spectra of galaxies, planetary nebula data and, especially, globular cluster data. We rely on both Newtonian and MOND frameworks and show their advantages and drawbacks. To infer the contribution of the dark component in early-type galaxies we rely on several stellar population synthesis models. It is shown that dark matter does not dominate in the inner regions of early-type galaxies, but becomes more important beyond three effective radii.

Stellar Population Synthesis in AGN Host Galaxies

2001 ◽  
Vol 1 ◽  
pp. 145-152
Author(s):  
M. Joly ◽  
C. Boisson ◽  
J. Moultaka ◽  
D. Pelat
Keyword(s):  
Stellar Population ◽  
Population Synthesis ◽  
Host Galaxies ◽  
Stellar Population Synthesis

scholarly journals Stellar population synthesis models between 2.5 and 5 μm based on the empirical IRTF stellar library

2015 ◽  
Vol 449 (3) ◽  
pp. 2853-2874 ◽  
Author(s):  
B. Röck ◽  
A. Vazdekis ◽  
R. F. Peletier ◽  
J. H. Knapen ◽  
J. Falcón-Barroso
Keyword(s):  
Stellar Population ◽  
Population Synthesis ◽  
Stellar Population Synthesis

scholarly journals Theory of multiple-stellar population synthesis in a non-Hamiltonian setting

New Astronomy ◽  
2019 ◽  
Vol 66 ◽  
pp. 20-30 ◽  
Author(s):  
S. Pasetto ◽  
D. Crnojević ◽  
G. Busso ◽  
C. Chiosi ◽  
L.P. Cassarà
Keyword(s):  
Stellar Population ◽  
Population Synthesis ◽  
Stellar Population Synthesis

scholarly journals Effects of the selection function on metallicity trends in spectroscopic surveys of the Milky Way

2017 ◽  
Vol 606 ◽  
pp. A97 ◽  
Author(s):  
G. Nandakumar ◽  
M. Schultheis ◽  
M. Hayden ◽  
A. Rojas-Arriagada ◽  
G. Kordopatis ◽  
...  
Keyword(s):  
Stellar Population ◽  
Milky Way ◽  
Target Selection ◽  
Selection Function ◽  
Population Synthesis ◽  
Sample Distribution ◽  
Stellar Population Synthesis ◽  
Source Sample ◽  
Correction Terms ◽  
Metallicity Distribution

Context. Large spectroscopic Galactic surveys imply a selection function in the way they performed their target selection. Aims. We investigate here the effect of the selection function on the metallicity distribution function (MDF) and on the vertical metallicity gradient by studying similar lines of sight using four different spectroscopic surveys (APOGEE, LAMOST, RAVE, and Gaia-ESO), which have different targeting strategies and therefore different selection functions. Methods. We use common fields between the spectroscopic surveys of APOGEE, LAMOST, RAVE (ALR) and APOGEE, RAVE, Gaia-ESO (AGR) and use two stellar population synthesis models, GALAXIA and TRILEGAL, to create mock fields for each survey. We apply the selection function in the form of colour and magnitude cuts of the respective survey to the mock fields to replicate the observed source sample. We make a basic comparison between the models to check which best reproduces the observed sample distribution. We carry out a quantitative comparison between the synthetic MDF from the mock catalogues using both models to understand the effect of the selection function on the MDF and on the vertical metallicity gradient. Results. Using both models, we find a negligible effect of the selection function on the MDF for APOGEE, LAMOST, and RAVE. We find a negligible selection function effect on the vertical metallicity gradients as well, though GALAXIA and TRILEGAL have steeper and shallower slopes, respectively, than the observed gradient. After applying correction terms on the metallicities of RAVE and LAMOST with respect to our reference APOGEE sample, our observed vertical metallicity gradients between the four surveys are consistent within 1σ. We also find consistent gradient for the combined sample of all surveys in ALR and AGR. We estimated a mean vertical metallicity gradient of − 0.241 ± 0.028 dex kpc-1. There is a significant scatter in the estimated gradients in the literature, but our estimates are within their ranges. Conclusions. We have shown that there is a negligible selection function effect on the MDF and the vertical metallicity gradients for APOGEE, RAVE, and LAMOST using two stellar population synthesis models. Therefore, it is indeed possible to combine common fields of different surveys in studies using MDF and metallicity gradients provided their metallicities are brought to the same scale.

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