Dark Matter Halos in Elliptical Galaxies

1993 ◽  
Vol 416 ◽  
pp. L45 ◽  
Author(s):  
Francesco Bertola ◽  
Alessandro Pizzella ◽  
Massimo Persic ◽  
Paolo Salucci
Keyword(s):  
Dark Matter ◽  
Elliptical Galaxies ◽  
Dark Matter Halos

scholarly journals Dark Matter Halos around Elliptical Galaxies: How Reliable Is the Stellar Kinematical Evidence?

2001 ◽  
Vol 563 (1) ◽  
pp. L19-L22 ◽  
Author(s):  
Maarten Baes ◽  
Herwig Dejonghe
Keyword(s):  
Dark Matter ◽  
Elliptical Galaxies ◽  
Dark Matter Halos

scholarly journals THE INTERGALACTIC STELLAR POPULATION FROM MERGERS OF ELLIPTICAL GALAXIES WITH DARK MATTER HALOS

2010 ◽  
Vol 710 (2) ◽  
pp. 1589-1595 ◽  
Author(s):  
A. Cesar González-García ◽  
Letizia Stanghellini ◽  
Arturo Manchado
Keyword(s):  
Dark Matter ◽  
Stellar Population ◽  
Elliptical Galaxies ◽  
Dark Matter Halos

scholarly journals Galaxy formation from dry and hydro simulations

2009 ◽  
Vol 5 (H15) ◽  
pp. 85-85
Author(s):  
Luca Ciotti
Keyword(s):  
Dark Matter ◽  
Galaxy Formation ◽  
Scaling Laws ◽  
High Redshift ◽  
Elliptical Galaxies ◽  
Dark Matter Halos ◽  
Galaxy Mergers ◽  
Lower Redshift

AbstractThe effects of dry and wet merging on the Scaling Laws (SLs) of elliptical galaxies (Es) are discussed. It is found that the SLs, possibly established at high redshift by the fast collapse of gas-rich and clumpy stellar distributions in preexisting dark matter halos following the cosmological SLs, are compatible with a (small) number of galaxy mergers at lower redshift.

scholarly journals Scaling Laws for Dark Matter Halos in Late-Type and Dwarf Spheroidal Galaxies

2014 ◽  
Vol 10 (S311) ◽  
pp. 72-77
Author(s):  
John Kormendy ◽  
K. C. Freeman
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Scaling Laws ◽  
Large Population ◽  
Elliptical Galaxies ◽  
Dark Matter Halos ◽  
Fundamental Plane ◽  
Dwarf Spheroidal Galaxies ◽  
Visible Matter ◽  
Luminous Galaxies

AbstractDark matter (DM) halos of Sc–Im galaxies satisfy structural scaling laws analogous to the fundamental plane relations for elliptical galaxies. Halos in less luminous galaxies have smaller core radii rc, higher central densities ρ^, and smaller central velocity dispersions σ. If dwarf spheroidal (dSph) and dwarf Magellanic irregular (dIm) galaxies lie on the extrapolations of these correlations, then we can estimate their baryon loss relative to that of Sc–Im galaxies. We find that, if there had been no enhanced baryon loss relative to Sc–Im galaxies, typical dSph and dIm galaxies would be brighter by ΔMB ≃ -4.0 mag and ΔMB ≃ -3.5 mag, respectively. Instead, the galaxies lost or retained as gas (in dIm galaxies) baryons that could have formed stars. Also, dSph and dIm galaxies have DM halos that are more massive than we thought, with σ ~ 30 km s−1 or circular-orbit rotation velocities Vcirc ~ 42 km s−1. Comparison of DM and visible matter parameter correlations confirms that, at MV ≳ -18, dSph and dIm galaxies form a sequence of decreasing baryon-to-DM mass ratios in smaller dwarfs. We show explicitly that galaxy baryon content goes to (almost) zero at Vcirc ≲ 42 ± 4 km s−1, in agreement with Vcirc as found from our estimate of baryon depletion. Our results suggest that there may be a large population of DM halos that are dark and undiscovered. This helps to solve the problem that the initial fluctuation spectrum of cold dark matter predicts more dwarf galaxies than we observe.

The shapes of simulated dark matter halos

2004 ◽  
Vol 220 ◽  
pp. 421-429 ◽  
Author(s):  
Volker Springel ◽  
Simon D. M. White ◽  
Lars Hernquist
Keyword(s):  
Dark Matter ◽  
Major Axis ◽  
Elliptical Galaxies ◽  
Radiative Cooling ◽  
Dark Halo ◽  
Dark Matter Halos ◽  
Robust Method ◽  
Shape Distribution ◽  
Measurement Uncertainties ◽  
Hydrodynamical Simulations

Dark matter halos formed in CDM simulations are known to have triaxial shapes, with substantial distortions from spherical symmetry. However, conflicting claims have been made with respect to radial variations of halo shape, or trends with mass. We propose a new, more robust method to determine halo shapes based on the gravitational potential, thereby avoiding measurement uncertainties that may be the cause of these discrepancies. We find a strong preference towards prolate halo shapes, with mean minor-to-major axis-ratios close to ~ 0.5. Spherical halos are generally very rare, but there is a trend for smaller mass systems to be less elongated. We also compare dark halo shapes found in hydrodynamical simulations that include radiative cooling, star formation, and feedback processes, with those measured in equivalent collisionless simulations. Dissipation makes dark halos substantially rounder at small radii, to the extent that their shape distribution matches that of elliptical galaxies.

scholarly journals The Ages of Elliptical Galaxies in a Merger Model

1996 ◽  
Vol 171 ◽  
pp. 265-273 ◽  
Author(s):  
G. Kauffmann
Keyword(s):  
Dark Matter ◽  
Star Formation ◽  
Early Phase ◽  
High Redshift ◽  
Elliptical Galaxies ◽  
Disk Galaxies ◽  
Dark Matter Halos ◽  
Formation History ◽  
History Of ◽  
Intense Star Formation

There have long been two competing views on the formation history of the ellipticals galaxies we see today. One is that most of the stars in present-day galactic bulges and ellipticals were produced during a relatively short, early phase of intense star formation at high redshift. The second view is that elliptical galaxies are relative latecomers, having been produced as the result of the merging of disk galaxies drawn together by gravity as their surrounding dark matter halos coalesced.

Constraints on the Clumpiness of Dark Matter Halos Through Heating of Disk Galaxies

2003 ◽  
Vol 10 ◽  
pp. 95-95
Author(s):  
E. Ardi ◽  
T. Tsuchiya ◽  
A. Burkert
Keyword(s):  
Dark Matter ◽  
Disk Galaxies ◽  
Dark Matter Halos

Constrained Simulations of Dark Matter Halos

2006 ◽  
Vol 20 ◽  
pp. 15-18
Author(s):  
Y. Hoffman ◽  
E. Romano-Díaz ◽  
A. Faltenbacher ◽  
D. Jones ◽  
C. Heller ◽  
...  
Keyword(s):  
Dark Matter ◽  
Dark Matter Halos

scholarly journals Modeling dark matter halos with nonlinear field theories

2021 ◽  
Vol 103 (10) ◽  
Author(s):  
R. A. C. Correa ◽  
P. H. R. S. Moraes ◽  
A. de Souza Dutra ◽  
O. L. Dors ◽  
W. de Paula ◽  
...  
Keyword(s):  
Dark Matter ◽  
Field Theories ◽  
Dark Matter Halos ◽  
Nonlinear Field

scholarly journals On the formation and stability of fermionic dark matter halos in a cosmological framework

2020 ◽  
Author(s):  
Carlos R Argüelles ◽  
Manuel I Díaz ◽  
Andreas Krut ◽  
Rafael Yunis
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Space Distribution ◽  
Coarse Grained ◽  
Dark Matter Halos ◽  
The Core ◽  
The Galaxy ◽  
Gravitating Systems ◽  
The Given ◽  
First Time

Abstract The formation and stability of collisionless self-gravitating systems is a long standing problem, which dates back to the work of D. Lynden-Bell on violent relaxation, and extends to the issue of virialization of dark matter (DM) halos. An important prediction of such a relaxation process is that spherical equilibrium states can be described by a Fermi-Dirac phase-space distribution, when the extremization of a coarse-grained entropy is reached. In the case of DM fermions, the most general solution develops a degenerate compact core surrounded by a diluted halo. As shown recently, the latter is able to explain the galaxy rotation curves while the DM core can mimic the central black hole. A yet open problem is whether this kind of astrophysical core-halo configurations can form at all, and if they remain stable within cosmological timescales. We assess these issues by performing a thermodynamic stability analysis in the microcanonical ensemble for solutions with given particle number at halo virialization in a cosmological framework. For the first time we demonstrate that the above core-halo DM profiles are stable (i.e. maxima of entropy) and extremely long lived. We find the existence of a critical point at the onset of instability of the core-halo solutions, where the fermion-core collapses towards a supermassive black hole. For particle masses in the keV range, the core-collapse can only occur for Mvir ≳ E9M⊙ starting at zvir ≈ 10 in the given cosmological framework. Our results prove that DM halos with a core-halo morphology are a very plausible outcome within nonlinear stages of structure formation.

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