scholarly journals Boson dark matter halos with a dominant noncondensed component

2021 ◽  
Vol 2021 (11) ◽  
pp. 055
Author(s):  
Iskander G. Abdullin ◽  
Vladimir A. Popov
Keyword(s):  
Dark Matter ◽  
Density Profile ◽  
Compact Objects ◽  
Dark Matter Halos ◽  
Galaxy Halos ◽  
Low Surface Brightness ◽  
Natural Mechanism ◽  
Bose Einstein ◽  
Low Surface Brightness Galaxies ◽  
Best Fit

Abstract We consider galaxy halos formed by dark matter bosons with mass in the range of about a few tens or hundreds eV. A major part of the particles is in a noncondensed state and described under the Thomas-Fermi approach. Derived equations are solved numerically to find the halo density profile. The noncondensed state is supported in the entire halo except compact gravitationally bounded Bose-Einstein condensates. Although the size of these compact objects, also known as Bose stars, depends on interactions between the particles, its upper limit is only about 100 astronomical units. The Bose stars collect the condensed bosons providing a density cusp avoidance in the halo as well as a natural mechanism to prevent overproduction of small halos. Clusters of the Bose stars can also contribute to the halo density profile. The model is analyzed by confronting its predictions with observations of galaxy rotation curves. We employ 22 low surface brightness galaxies and obtain that the model is consistent with the observational data when the particle mass is in the range above about 50 eV and the best fit corresponds to the mass m = 86 eV. This mass is appropriate for relic dark matter bosons, which decouple just after QCD phase transition.

scholarly journals Constraints on the Structure of Dark Matter Halos from the Rotation Curves of Low Surface Brightness Galaxies

2000 ◽  
Vol 119 (4) ◽  
pp. 1579-1591 ◽  
Author(s):  
Frank C. van den Bosch ◽  
Brant E. Robertson ◽  
Julianne J. Dalcanton ◽  
W. J. G. de Blok
Keyword(s):  
Dark Matter ◽  
Surface Brightness ◽  
Dark Matter Halos ◽  
Rotation Curves ◽  
Low Surface Brightness ◽  
Low Surface Brightness Galaxies

scholarly journals The dark matter halos of the bluest low surface brightness galaxies

2006 ◽  
Vol 452 (3) ◽  
pp. 857-868 ◽  
Author(s):  
E. Zackrisson ◽  
N. Bergvall ◽  
T. Marquart ◽  
G. Östlin
Keyword(s):  
Dark Matter ◽  
Surface Brightness ◽  
Dark Matter Halos ◽  
Low Surface Brightness ◽  
Low Surface Brightness Galaxies

scholarly journals The Central Dynamics of Blue Low Surface Brightness Galaxies

2004 ◽  
Vol 220 ◽  
pp. 335-336
Author(s):  
Erik Zackrisson ◽  
Nils Bergvall
Keyword(s):  
Dark Matter ◽  
Density Profile ◽  
Surface Brightness ◽  
Cold Dark Matter ◽  
Central Density ◽  
Disk Galaxies ◽  
Rotation Curves ◽  
Central Surface ◽  
Low Surface Brightness ◽  
Low Surface Brightness Galaxies

We use optical, long-slit rotation curves to derive the slope of the central density profile in three blue disk galaxies with very faint central surface brightness values. We find the result to be in conflict with current cold dark matter predictions and to lend further support for pseudo-isothermal spheres as superior models for the dark halos of galaxies.

scholarly journals The formation of ultradiffuse galaxies in the RomulusC galaxy cluster simulation

2020 ◽  
Vol 497 (3) ◽  
pp. 2786-2810 ◽  
Author(s):  
M Tremmel ◽  
A C Wright ◽  
A M Brooks ◽  
F Munshi ◽  
D Nagai ◽  
...  
Keyword(s):  
Dark Matter ◽  
Stellar Evolution ◽  
Dwarf Galaxies ◽  
Galaxy Cluster ◽  
High Mass ◽  
Tidal Interactions ◽  
Low Surface Brightness ◽  
Low Mass ◽  
Tidal Heating ◽  
Low Surface Brightness Galaxies

ABSTRACT We study the origins of 122 ultradiffuse galaxies (UDGs) in the Romulus c zoom-in cosmological simulation of a galaxy cluster (M200 = 1.15 × 1014 M⊙), one of the only such simulations capable of resolving the evolution and structure of dwarf galaxies (M⋆ < 109 M⊙). We find broad agreement with observed cluster UDGs and predict that they are not separate from the overall cluster dwarf population. UDGs in cluster environments form primarily from dwarf galaxies that experienced early cluster in-fall and subsequent quenching due to ram pressure. The ensuing dimming of these dwarf galaxies due to passive stellar evolution results in a population of very low surface brightness galaxies that are otherwise typical dwarfs. UDGs and non-UDGs alike are affected by tidal interactions with the cluster potential. Tidal stripping of dark matter, as well as mass-loss from stellar evolution, results in the adiabatic expansion of stars, particularly in the lowest mass dwarfs. High-mass dwarf galaxies show signatures of tidal heating while low-mass dwarfs that survive until z = 0 typically have not experienced such impulsive interactions. There is little difference between UDGs and non-UDGs in terms of their dark matter haloes, stellar morphology, colours, and location within the cluster. In most respects cluster UDG and non-UDGs alike are similar to isolated dwarf galaxies, except for the fact that they are typically quenched.

scholarly journals DARK MATTER AXIONS

2010 ◽  
Vol 25 (02n03) ◽  
pp. 554-563 ◽  
Author(s):  
P. SIKIVIE
Keyword(s):  
Dark Matter ◽  
Particle Physics ◽  
Cold Dark Matter ◽  
Einstein Condensate ◽  
Dark Matter Halos ◽  
Linear Regime ◽  
Bose Einstein Condensate ◽  
Invisible Axion ◽  
Bose Einstein ◽  
The Universe

The hypothesis of an 'invisible' axion was made by Misha Shifman and others, approximately thirty years ago. It has turned out to be an unusually fruitful idea, crossing boundaries between particle physics, astrophysics and cosmology. An axion with mass of order 10-5 eV (with large uncertainties) is one of the leading candidates for the dark matter of the universe. It was found recently that dark matter axions thermalize and form a Bose-Einstein condensate (BEC). Because they form a BEC, axions differ from ordinary cold dark matter (CDM) in the non-linear regime of structure formation and upon entering the horizon. Axion BEC provides a mechanism for the production of net overall rotation in dark matter halos, and for the alignment of cosmic microwave anisotropy multipoles. Because there is evidence for these phenomena, unexplained with ordinary CDM, an argument can be made that the dark matter is axions.

scholarly journals Density profile asymptotes at the centre of dark matter halos

2003 ◽  
Vol 404 (3) ◽  
pp. 809-814 ◽  
Author(s):  
J. P. Mücket ◽  
M. Hoeft
Keyword(s):  
Dark Matter ◽  
Density Profile ◽  
Dark Matter Halos

scholarly journals Universal relations with fermionic dark matter

2018 ◽  
Vol 168 ◽  
pp. 04015
Author(s):  
A. Krut ◽  
C. R. Argüelles ◽  
J. A. Rueda ◽  
R. Ruffini
Keyword(s):  
Dark Matter ◽  
Finite Size ◽  
Elliptical Galaxies ◽  
Compact Objects ◽  
Space Distribution ◽  
Fermion Mass ◽  
Fermion Masses ◽  
Natural Mechanism ◽  
First Time ◽  
Good Agreement

We have recently introduced a new model for the distribution of dark matter (DM) in galaxies, the Ruffini-Argüelles-Rueda (RAR) model, based on a self-gravitating system of massive fermions at finite temperatures. The RAR model, for fermion masses above keV, successfully describes the DM halos in galaxies, and predicts the existence of a denser quantum core towards the center of each configuration. We demonstrate here, for the first time, that the introduction of a cutoff in the fermion phase-space distribution, necessary to account for galaxies finite size and mass, defines a new solution with a compact quantum core which represents an alternative to the central black hole (BH) scenario for SgrA*. For a fermion mass in the range 48keV ≤ mc2 ≤ 345keV, the DM halo distribution fulfills the most recent data of the Milky Way rotation curves while harbors a dense quantum core of 4×106M⊙ within the S2 star pericenter. In particular, for a fermion mass of mc2 ∼ 50keV the model is able to explain the DM halos from typical dwarf spheroidal to normal elliptical galaxies, while harboring dark and massive compact objects from ∼ 103M⊙ tp to 108M⊙ at their respective centers. The model is shown to be in good agreement with different observationally inferred universal relations, such as the ones connecting DM halos with supermassive dark central objects. Finally, the model provides a natural mechanism for the formation of supermassive BHs as heavy as few ∼ 108M⊙. We argue that larger BH masses (few ∼ 109−10M⊙) may be achieved by assuming subsequent accretion processes onto the above heavy seeds, depending on accretion efficiency and environment.

scholarly journals A Halo Occupation Interpretation of Quasars at z ∼ 1.5 Using Very Small-Scale Clustering Information

2019 ◽  
Vol 486 (1) ◽  
pp. 274-282 ◽  
Author(s):  
S Eftekharzadeh ◽  
A D Myers ◽  
E Kourkchi
Keyword(s):  
Dark Matter ◽  
Density Profile ◽  
Small Scale ◽  
Minimum Mass ◽  
Concentration Parameter ◽  
Free Parameters ◽  
The One ◽  
Halo Occupation Distribution ◽  
Best Fit

Abstract We combine the most precise small-scale ($\lt 100\, \rm h^{-1}kpc$) quasar clustering constraints to date with recent measurements at large scales ($\gt 1\, \rm h^{-1}Mpc$) from the extended Baryon Oscillation Spectroscopic Survey (eBOSS) to better constrain the satellite fraction of quasars at z ∼ 1.5 in the halo occupation formalism. We build our Halo Occupation Distribution (HOD) framework based on commonly used analytic forms for the one and two-halo terms with two free parameters: the minimum halo mass that hosts a central quasar and the fraction of satellite quasars that are within one halo. Inspired by recent studies that propose a steeper density profile for the dark matter haloes that host quasars, we explore HOD models at kiloparsec scales and best-fit parameters for models with 10 × higher concentration parameter. We find that an HOD model with a satellite fraction of $f_{\rm sat} = 0.071_{-0.004}^{+0.009}$ and minimum mass of $\rm M_{m} = 2.31_{-0.38}^{+0.41} \times 10^{12}\, \, \rm h^{-1} M_{\odot }$ for the host dark matter haloes best describes quasar clustering (on all scales) at z ∼ 1.5. Our results are marginally inconsistent with earlier work that studied brighter quasars, hinting at a luminosity-dependence to the one-halo term.

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