scholarly journals Implication of Dark Matter Content in Dwarf Spheroidal Galaxies

1999 ◽  
Vol 192 ◽  
pp. 402-408
Author(s):  
H. Hirashita ◽  
T. T. Takeuchi ◽  
H. Kamaya
Keyword(s):  
Dark Matter ◽  
Local Group ◽  
Matter Content ◽  
Dwarf Spheroidal Galaxies ◽  
Large Velocity ◽  
The Galaxy ◽  
Correlation Tests ◽  
Tidal Heating ◽  
Physical Quantities ◽  
Spheroidal Galaxies

We investigate the dark matter (DM) content in the Local Group dwarf spheroidal galaxies (dSphs) by examining the correlations among their physical quantities. Two origins of the large velocity dispersions of the dSphs are possible: [1] the existence of DM and [2] tidal heating by the Galaxy. The correlation tests support both [1] and [2]. We finally mention circumstantial evidence for the existence of DM in the dSphs.

scholarly journals Evidence for Light-weight Local Group Dwarf Spheroidal Galaxies

2004 ◽  
Vol 220 ◽  
pp. 365-366
Author(s):  
J. R. Kuhn ◽  
D. Kocevski
Keyword(s):  
Dark Matter ◽  
Milky Way ◽  
Local Group ◽  
Light Weight ◽  
Natural Explanation ◽  
Dwarf Spheroidal Galaxies ◽  
Ursa Minor ◽  
Matter Component ◽  
Morphological State ◽  
Spheroidal Galaxies

A simple and natural explanation for the dynamics and morphology of the Local Group Dwarf Spheroidal galaxies, Draco (Dra) and Ursa Minor (UMi), is that they are weakly unbound stellar systems with no significant dark matter component. A gentle, but persistent, Milky Way (MW) tide has left them in their current kinematic and morphological state (the “parametric tidal excitation”). A new test of a dark matter dominated dS potential follows from a careful observation of the “clumpiness” of the dS stellar surface density.

scholarly journals An Estimate of the Dark-Matter Content in the Galaxy

1995 ◽  
Vol 164 ◽  
pp. 394-394
Author(s):  
Slobodan Ninković
Keyword(s):  
Dark Matter ◽  
Total Mass ◽  
Milky Way ◽  
Local Group ◽  
Matter Content ◽  
Escape Velocity ◽  
The Galaxy

The total mass of the Milky-Way dark corona and its contribution to the total mass of the Galaxy, is estimated by combining the limits imposed by the Local Group as probably bound and the constraints on the local escape velocity. The results: total mass of the Milky Way about 1.6 TM⊙ (dark corona over 1.5 TM⊙; T = 1012), local escape velocity about 600 kms−1.

scholarly journals Dark matter distribution and dynamics of dwarf spheroidal galaxies

2019 ◽  
Vol 14 (S353) ◽  
pp. 239-245
Author(s):  
Ewa L. Łokas
Keyword(s):  
Dark Matter ◽  
Velocity Dispersion ◽  
Matter Content ◽  
Current Status ◽  
Superposition Method ◽  
Matter Distribution ◽  
Dwarf Spheroidal Galaxies ◽  
Dark Matter Distribution ◽  
Dynamical Modelling ◽  
Spheroidal Galaxies

AbstractI review the current status of dynamical modelling of dwarf spheroidal galaxies focusing on estimates of their dark matter content. Starting with the simplest methods using the velocity dispersion profiles I discuss the inherent issues of mass-anisotropy degeneracy and contamination by unbound stars. I then move on to methods of increasing complexity, aiming to break the degeneracy, up to recent applications of the Schwarzschild orbit superposition method. The dynamical modelling is placed in the context of possible scenarios for the formation of dwarf spheroidal galaxies, including the tidal stirring model and mergers of dwarf galaxies. The two scenarios are illustrated with examples from simulations: a comparison between the tidal evolution of dwarfs with cuspy and cored dark matter profiles and the formation of a dwarf spheroidal with prolate rotation.

scholarly journals Observed Properties of Dark Matter on Small Spatial Scales

2007 ◽  
Vol 3 (S244) ◽  
pp. 44-52 ◽  
Author(s):  
Rosemary F.G. Wyse ◽  
Gerard Gilmore
Keyword(s):  
Dark Matter ◽  
Galaxy Evolution ◽  
Local Group ◽  
Spatial Scales ◽  
Critical Role ◽  
Large Datasets ◽  
Dwarf Spheroidal Galaxies ◽  
Internal Motions ◽  
Spheroidal Galaxies

AbstractThe nature of dark matter is one of the outstanding questions of astrophysics. The internal motions of member stars reveal that the lowest luminosity galaxies in the Local Group are the most dark-matter dominated. New large datasets allow one to go further, and determine systematic properties of their dark matter haloes. We summarise recent results, emphasising the critical role of the dwarf spheroidal galaxies in understanding both dark matter and baryonic processes that shape galaxy evolution.

scholarly journals About the morphology of dwarf spheroidal galaxies and their dark matter content

2003 ◽  
Vol 406 (3) ◽  
pp. 847-854 ◽  
Author(s):  
C. J. Walcher ◽  
J. W. Fried ◽  
A. Burkert ◽  
R. S. Klessen
Keyword(s):  
Dark Matter ◽  
Matter Content ◽  
Dwarf Spheroidal Galaxies ◽  
Spheroidal Galaxies

scholarly journals Pushing back the limits: detailed properties of dwarf galaxies in a ΛCDM universe

2018 ◽  
Vol 616 ◽  
pp. A96 ◽  
Author(s):  
Yves Revaz ◽  
Pascale Jablonka
Keyword(s):  
Star Formation ◽  
Local Group ◽  
Dwarf Galaxies ◽  
Mass Scale ◽  
Dwarf Spheroidal Galaxies ◽  
The Galaxy ◽  
Dynamical Simulations ◽  
Ursa Minor ◽  
Stellar Properties ◽  
Star Formation Histories

We present the results of a set of high-resolution chemo-dynamical simulations of dwarf galaxies in a ΛCDM cosmology. Out of an original (3.4 Mpc/h)3 cosmological box, a sample of 27 systems are re-simulated from z = 70 to z = 0 using a zoom-in technique. Gas and stellar properties are confronted to the observations in the greatest details: in addition to the galaxy global properties, we investigated the model galaxy velocity dispersion profiles, half-light radii, star formation histories, stellar metallicity distributions, and [Mg/Fe] abundance ratios. The formation and sustainability of the metallicity gradients and kinematically distinct stellar populations are also tackled. We show how the properties of six Local Group dwarf galaxies, NGC 6622, Andromeda II, Sculptor, Sextans, Ursa Minor and Draco are reproduced, and how they pertain to three main galaxy build-up modes. Our results indicate that the interaction with a massive central galaxy could be needed for a handful of Local Group dwarf spheroidal galaxies only, the vast majority of the systems and their variety of star formation histories arising naturally from a ΛCDM framework. We find that models fitting well the local Group dwarf galaxies are embedded in dark haloes of mass between 5 × 108 to a few 109 M⊙, without any missing satellite problem. We confirm the failure of the abundance matching approach at the mass scale of dwarf galaxies. Some of the observed faint however gas-rich galaxies with residual star formation, such as Leo T and Leo P, remain challenging. They point out the need of a better understanding of the UV-background heating.

scholarly journals J-factors for self-interacting dark matter in 20 dwarf spheroidal galaxies

2018 ◽  
Vol 98 (4) ◽  
Author(s):  
Sebastian Bergström ◽  
Riccardo Catena ◽  
Andrea Chiappo ◽  
Jan Conrad ◽  
Björn Eurenius ◽  
...  
Keyword(s):  
Dark Matter ◽  
Dwarf Spheroidal Galaxies ◽  
Spheroidal Galaxies
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