On the formation and stability of fermionic dark matter haloes in a cosmological framework
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 sp...
| Autores principales: | , , , |
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| Formato: | Articulo |
| Lenguaje: | Inglés |
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2021
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| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/125050 |
| Aporte de: |
| id |
I19-R120-10915-125050 |
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| record_format |
dspace |
| institution |
Universidad Nacional de La Plata |
| institution_str |
I-19 |
| repository_str |
R-120 |
| collection |
SEDICI (UNLP) |
| language |
Inglés |
| topic |
Ciencias Astronómicas Methods: numerical Galaxies: haloes Galaxies: nuclei Galaxies: formation Galaxies: structure Dark matter |
| spellingShingle |
Ciencias Astronómicas Methods: numerical Galaxies: haloes Galaxies: nuclei Galaxies: formation Galaxies: structure Dark matter Argüelles, Carlos Raúl Díaz, Manuel Krut, Andreas Yunis, Rafael On the formation and stability of fermionic dark matter haloes in a cosmological framework |
| topic_facet |
Ciencias Astronómicas Methods: numerical Galaxies: haloes Galaxies: nuclei Galaxies: formation Galaxies: structure Dark matter |
| description |
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≳109M⊙ 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. |
| format |
Articulo Articulo |
| author |
Argüelles, Carlos Raúl Díaz, Manuel Krut, Andreas Yunis, Rafael |
| author_facet |
Argüelles, Carlos Raúl Díaz, Manuel Krut, Andreas Yunis, Rafael |
| author_sort |
Argüelles, Carlos Raúl |
| title |
On the formation and stability of fermionic dark matter haloes in a cosmological framework |
| title_short |
On the formation and stability of fermionic dark matter haloes in a cosmological framework |
| title_full |
On the formation and stability of fermionic dark matter haloes in a cosmological framework |
| title_fullStr |
On the formation and stability of fermionic dark matter haloes in a cosmological framework |
| title_full_unstemmed |
On the formation and stability of fermionic dark matter haloes in a cosmological framework |
| title_sort |
on the formation and stability of fermionic dark matter haloes in a cosmological framework |
| publishDate |
2021 |
| url |
http://sedici.unlp.edu.ar/handle/10915/125050 |
| work_keys_str_mv |
AT arguellescarlosraul ontheformationandstabilityoffermionicdarkmatterhaloesinacosmologicalframework AT diazmanuel ontheformationandstabilityoffermionicdarkmatterhaloesinacosmologicalframework AT krutandreas ontheformationandstabilityoffermionicdarkmatterhaloesinacosmologicalframework AT yunisrafael ontheformationandstabilityoffermionicdarkmatterhaloesinacosmologicalframework |
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Repositorios |
| _version_ |
1764820451461169152 |