scholarly journals Baryons and Dark Matter halo distributions in ΛCDM Cosmology

2009 ◽  
Vol 5 (S262) ◽  
pp. 404-405
Author(s):  
Susana Pedrosa ◽  
Patricia Tissera ◽  
Cecilia Scannapieco
Keyword(s):  
Dark Matter ◽  
Angular Momentum ◽  
Momentum Transfer ◽  
Dark Matter Halo ◽  
Angular Momentum Transfer ◽  
History Of ◽  
Baryonic Mass ◽  
History Of Formation

AbstractWe analyse the dark matter (DM) distribution in a ≈1012M⊙ halo extracted from a simulation consistent with the concordance cosmology, where the physics regulating the transformation of gas into stars was allowed to change producing galaxies with different morphologies. Although the DM profiles get more concentrated as baryons are collected at the centre of the haloes compared to a pure dynamical run, the total baryonic mass alone is not enough to fully predict the reaction of the DM profile. Our findings suggest that the response of the DM halo is driven by the history of assembly of baryons into a galaxy. The accretion of satellites could be associated with an expansion of the dark matter profiles, triggered by angular momentum transfer from the incoming satellites. However, we also found that these mechanism have different efficiencies which are set by the history of formation of the structure.

scholarly journals Dark matter bars in spinning haloes

2019 ◽  
Vol 488 (4) ◽  
pp. 5788-5801 ◽  
Author(s):  
Angela Collier ◽  
Isaac Shlosman ◽  
Clayton Heller
Keyword(s):  
Dark Matter ◽  
Angular Momentum ◽  
Momentum Transfer ◽  
Direct Detection ◽  
Maximal Amplitude ◽  
Angular Momentum Transfer ◽  
Secular Evolution ◽  
Secondary Resonances ◽  
Spin Parameter ◽  
Resonance Transfer

ABSTRACT We study non-linear response of spinning dark matter (DM) haloes to dynamic and secular evolution of stellar bars in the embedded galactic discs, using high-resolution numerical simulations. For a sequence of haloes with the cosmological spin parameter λ = 0–0.09, and a representative angular momentum distribution, we analyse evolution of induced DM bars amplitude and quantify parameters of the response as well as trapping of DM orbits and angular momentum transfer by the main and secondary resonances. We find that (1) maximal amplitude of DM bars depends strongly on λ, while that of the stellar bars is indifferent to λ; (2) efficiency of resonance trapping of DM orbits by the bar increases with λ, and so is the mass and the volume of DM bars; (3) contribution of resonance transfer of angular momentum to the DM halo increases with λ, and for larger spin, the DM halo ‘talks’ to itself, by moving the angular momentum to larger radii – this process is maintained by resonances; and (4) prograde and retrograde DM orbits play different roles in angular momentum transfer. The ‘active’ part of the halo extends well beyond the bar region, up to few times the bar length in equatorial plane and away from this plane. (5) We model evolution of discless DM haloes and haloes with frozen discs, and found them to be perfectly stable to any Fourier modes. Finally, further studies adopting a range of mass and specific angular momentum distributions of the DM halo will generalize the dependence of DM response on the halo spin and important implications for direct detection of DM and that of the associated stellar tracers, such as streamers.

scholarly journals Angular Momentum Transfer in Dark Matter Halos: Erasing the Cusp

2006 ◽  
Vol 649 (2) ◽  
pp. 591-598 ◽  
Author(s):  
C. Tonini ◽  
A. Lapi ◽  
P. Salucci
Keyword(s):  
Dark Matter ◽  
Angular Momentum ◽  
Momentum Transfer ◽  
Dark Matter Halos ◽  
Angular Momentum Transfer

scholarly journals Dark matter response to galaxy assembly history

2019 ◽  
Vol 622 ◽  
pp. A197 ◽  
Author(s):  
María Celeste Artale ◽  
Susana E. Pedrosa ◽  
Patricia B. Tissera ◽  
Pedro Cataldi ◽  
Arianna Di Cintio
Keyword(s):  
Dark Matter ◽  
Stellar Mass ◽  
Dark Matter Halo ◽  
Stable Configuration ◽  
The Galaxy ◽  
Central Regions ◽  
Grid Scheme ◽  
History Of ◽  
Galaxy Assembly ◽  
Baryonic Mass

Aims. It is well known that the presence of baryons affects the dark matter host haloes. Exploring the galaxy assembly history together with the dark matter haloes properties through time can provide a way to measure these effects. Methods. We have studied the properties of four Milky Way mass dark matter haloes from the Aquarius project during their assembly history, between z = 0 − 4. In this work, we used a published SPH run and the dark matter only counterpart as case studies. To asses the robustness of our findings, we compared them with one of the haloes run using a moving-mesh technique and different sub-grid scheme. Results. Our results show that the cosmic evolution of the dark matter halo profiles depends on the assembly history of the baryons. We find that the dark matter profiles do not significantly change with time, hence they become stable, when the fraction of baryons accumulated in the central regions reaches 80 per cent of its present mass within the virial radius. Furthermore, the mass accretion history shows that the haloes that assembled earlier are those that contain a larger amount of baryonic mass aforetime, which in turn allows the dark matter halo profiles to reach a stable configuration earlier. For the SPH haloes, we find that the specific angular momentum of the dark matter particles within the five per cent of the virial radius at z = 0, remains approximately constant from the time at which 60 per cent of the stellar mass is gathered. We have explored different theoretical and empirical models for the contraction of the haloes through redshift. A model to better describe the contraction of the haloes through redshift evolution must depend on the stellar mass content in the inner regions.

scholarly journals Using torque to understand barred galaxy models

2019 ◽  
Vol 490 (3) ◽  
pp. 3616-3632 ◽  
Author(s):  
Michael S Petersen ◽  
Martin D Weinberg ◽  
Neal Katz
Keyword(s):  
Angular Momentum ◽  
Steady State ◽  
Momentum Transfer ◽  
Galaxy Evolution ◽  
Equilibrium Phase ◽  
Dark Matter Halo ◽  
Central Density ◽  
State Equilibrium ◽  
Barred Galaxies ◽  
Angular Momentum Transfer

ABSTRACTWe track the angular momentum transfer in N-body simulations of barred galaxies by measuring torques to understand the dynamical mechanisms responsible for the evolution of the bar–disc–dark matter halo system. We find evidence for three distinct phases of barred galaxy evolution: assembly, secular growth, and steady-state equilibrium. Using a decomposition of the disc into orbital families, we track bar mass and angular momentum through time and correlate the quantities with the phases of evolution. We follow the angular momentum transfer between particles and identify the dominant torque channels. We find that the halo model mediates the assembly and growth of the bar for a high central density halo, and the outer disc mediates the assembly and growth of the bar in a low central density halo model. Both galaxies exhibit a steady-state equilibrium phase where the bar is neither lengthening nor slowing. The steady-state equilibrium results from the balance of torque between particles that are gaining and losing angular momentum. We propose observational metrics for barred galaxies that can be used to help determine the evolutionary phase of a barred galaxy, and discuss the implications of the phases for galaxy evolution as a whole.

scholarly journals Spin-lattice dynamics model with angular momentum transfer for canonical and microcanonical ensembles

2021 ◽  
Vol 103 (2) ◽  
Author(s):  
Mara Strungaru ◽  
Matthew O. A. Ellis ◽  
Sergiu Ruta ◽  
Oksana Chubykalo-Fesenko ◽  
Richard F. L. Evans ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Momentum Transfer ◽  
Lattice Dynamics ◽  
Dynamics Model ◽  
Angular Momentum Transfer ◽  
Spin Lattice

scholarly journals Angular momentum transfer and partition in the deep-inelastic reaction 664 MeV 84Kr + natAg

1981 ◽  
Vol 371 (3) ◽  
pp. 510-532 ◽  
Author(s):  
L.G. Sobotka ◽  
C.C. Hsu ◽  
G.J. Wozniak ◽  
D.J. Morrissey ◽  
L.G. Moretto
Keyword(s):  
Angular Momentum ◽  
Momentum Transfer ◽  
Angular Momentum Transfer ◽  
Inelastic Reaction ◽  
Deep Inelastic Reaction
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