scholarly journals Galactic magnetic fields in the context of dark matter. Influence on the rotation curves of spiral galaxies.

2019 ◽  
Author(s):  
Lukasz Bratek ◽  
Joanna Jalocha
Keyword(s):  
Dark Matter ◽  
Magnetic Fields ◽  
Spiral Galaxies ◽  
Rotation Curves ◽  
Galactic Magnetic Fields

Magnetic fields as an alternative explanation for the rotation curves of spiral galaxies

Nature ◽  
1992 ◽  
Vol 360 (6405) ◽  
pp. 652-653 ◽  
Author(s):  
E. Battaner ◽  
J. L. Garrido ◽  
M. Membrado ◽  
E. Florido
Keyword(s):  
Magnetic Fields ◽  
Alternative Explanation ◽  
Spiral Galaxies ◽  
Rotation Curves

scholarly journals Could galactic magnetic fields be generated by charged ultra-light boson dark matter?

2019 ◽  
Vol 79 (10) ◽  
Author(s):  
Maribel Hernández ◽  
Ana A. Avilez ◽  
Tonatiuh Matos
Keyword(s):  
Dark Matter ◽  
Scalar Field ◽  
Magnetic Fields ◽  
Density Profile ◽  
Dark Matter Halo ◽  
Error Estimator ◽  
Rotation Curves ◽  
Complex Scalar ◽  
Virtual Photons ◽  
Klein Gordon

Abstract We study the possibility that large-scale magnetic fields observed in galaxies could be produced by a dark matter halo made of charged ultra-light bosons, that arise as excitations of a complex scalar field described by the Klein–Gordon equation with local U(1) symmetry which introduces electromagnetic fields that minimally couple to the complex scalar current and act as dark virtual photons. These virtual photons have an unknown coupling constant with real virtual photons. We constrain the final interaction using the observed magnetic fields in galaxies. We use classical solutions of the Klein–Gordon–Maxwell system to describe the density profile of dark matter and magnetic fields in galaxies. We consider two cases assuming spherical and dipolar spatial symmetries. For the LSB spherical galaxy F563-V2, we test the sensitivity of the predicted rotation curves in the charged Scalar Field Dark Matter (cSFDM) model to variations of the electromagnetic coupling and using the Fisher matrix error estimator, we set a constraint over that coupling by requiring that theoretical rotation curves lay inside the $$1\sigma $$1σ confidence region of observational data. We find that cSFDM haloes generate magnetic fields of the order of $$\mu G$$μG and reproduce the observed rotation curves of F563-V2 if the ultra-light boson has a charge $$\sim <10^{-13}e$$∼<10-13e for the monopole-like density profile and $$\sim <10^{-14}e$$∼<10-14e for the dipole-like one.

scholarly journals Galaxy rotation curves using a non-parametric regression method: core, cuspy and fuzzy scalar field dark matter models

2019 ◽  
Vol 488 (4) ◽  
pp. 5127-5144 ◽  
Author(s):  
Lizbeth M Fernández-Hernández ◽  
Ariadna Montiel ◽  
Mario A Rodríguez-Meza
Keyword(s):  
Dark Matter ◽  
Selection Criteria ◽  
Spiral Galaxies ◽  
Information Criterion ◽  
Volume Density ◽  
Rotation Curves ◽  
Fuzzy Models ◽  
Galaxy Rotation Curves ◽  
Statistical Criteria ◽  
Non Parametric

ABSTRACT We present a non-parametric reconstruction of the rotation curves (RCs) for 88 spiral galaxies using the LOESS (locally weighted scatterplot smoothing) + SIMEX (simulation and extrapolation) technique. In order to compare methods, we also use a parametric approach, assuming core and cuspy dark matter (DM) profiles: pseudo-isothermal (PISO), Navarro−Frenk–White (NFW), Burkert, Spano, the soliton, and two fuzzy soliton + NFW. As a result of these two approaches, a comparison of the RCs obtained is carried out by computing the distance between the central curves and the distance between the 1σ error bands. Furthermore, we perform a model selection according to two statistical criteria, the Bayesian information criterion and the value of $\chi ^2_{\rm red}$. We work with two groups. The first is a comparison between PISO, NFW, Spano and Burkert, showing that Spano is the most favoured model satisfying our selection criteria. For the second group, we select the soliton, NFW and fuzzy models, resulting in soliton as the best model. Moreover, according to the statistical tools and non-parametric reconstruction, we are able to classify galaxies as core or cuspy. Finally, using a Markov chain Monte Carlo method, for each of the DM models we compute the characteristic surface density, μDM = ρsrs, and the mass within 300 pc. We find that there is a common mass for spiral galaxies of the order of 107 M⊙, which is in agreement with results for dSph Milky Way satellites, independent of the model. This result is also consistent with our finding that there is a constant characteristic volume density of haloes. Finally, we also find that μDM is not constant, which is in tension with the literature.

scholarly journals Cores vs. Cusps: Dark Matter Density Profiles in Spirals

2004 ◽  
Vol 220 ◽  
pp. 311-312
Author(s):  
Gianfranco Gentile ◽  
Uli Klein ◽  
Paolo Salucci ◽  
Daniela Vergani
Keyword(s):  
Dark Matter ◽  
Rotation Curve ◽  
Spiral Galaxies ◽  
Matter Density ◽  
Matter Distribution ◽  
Rotation Curves ◽  
Density Profiles ◽  
The Core ◽  
Dark Matter Distribution ◽  
A New Technique

We use photometric, Hα and Hi data to investigate the distribution of dark matter in spiral galaxies. A new technique for deriving the Hi rotation curve is presented. the final combined Hα+Hi rotation curves are symmetric, well resolved and extend to large radii. We perform the rotation curve decomposition into the luminous and dark matter contributions. the observations are confronted with different models of the dark matter distribution, including core-dominated and cusp-dominated halos as well as less conventional possibilities. the best agreement with the observations is found for the core-dominated halos.

scholarly journals Constraints on the Dark Matter from Optical Rotation Curves

1987 ◽  
Vol 117 ◽  
pp. 51-65 ◽  
Author(s):  
Vera C. Rubin
Keyword(s):  
Dark Matter ◽  
Spiral Galaxies ◽  
Optical Rotation ◽  
Optical Image ◽  
Rotation Curves

From the observed rotation curves of Sa, Sb, and Sc spiral galaxies, it is possible to deduce a dozen constraints on the nonluminous matter in spirals. Within the optical image, the dark matter is less concentrated than the luminous, and contributes about 1/2 of the mass, for spirals of all Hubble types and luminosities.

scholarly journals Galactic Dynamos Without Sharp Boundaries: Non-Axisymmetric Fields in Axisymmetric Disks?

1990 ◽  
Vol 140 ◽  
pp. 115-116
Author(s):  
R. Meinel ◽  
D. Elstner ◽  
G. Rüdiger ◽  
F. Krause
Keyword(s):  
Magnetic Fields ◽  
Large Scale ◽  
Spiral Galaxies ◽  
Galactic Magnetic Fields ◽  
Axisymmetric Structure ◽  
Galactic Dynamos

Radio polarization observations of spiral galaxies suggest the existence of large-scale galactic magnetic fields which are of either axisymmetric -spiral (ASS) or bisymmetric-spiral (BSS), i.e. non-axisymmetric, structure (cf. Beck, 1939). Clear evidence for a BSS field was indicated for M31 by M. Krause et al. (1989).

scholarly journals Dark matter and generation of galactic magnetic fields

2013 ◽  
Vol 73 (10) ◽  
Author(s):  
Zurab Berezhiani ◽  
A. D. Dolgov ◽  
I. I. Tkachev
Keyword(s):  
Dark Matter ◽  
Magnetic Fields ◽  
Galactic Magnetic Fields

scholarly journals Tidal Dwarf Galaxies and Missing Baryons

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Frederic Bournaud
Keyword(s):  
Dark Matter ◽  
Spiral Galaxies ◽  
Dwarf Galaxies ◽  
High Redshift ◽  
Rotation Curves ◽  
Cosmological Problem ◽  
Flat Rotation Curves ◽  
Mass Size ◽  
Merger Rate ◽  
The Universe

Tidal dwarf galaxies form during the interaction, collision, or merger of massive spiral galaxies. They can resemble “normal” dwarf galaxies in terms of mass, size, and become dwarf satellites orbiting around their massive progenitor. They nevertheless keep some signatures from their origin, making them interesting targets for cosmological studies. In particular, they should be free from dark matter from a spheroidal halo. Flat rotation curves and high dynamical masses may then indicate the presence of an unseen component, and constrain the properties of the “missing baryons,” known to exist but not directly observed. The number of dwarf galaxies in the Universe is another cosmological problem for which it is important to ascertain if tidal dwarf galaxies formed frequently at high redshift, when the merger rate was high, and many of them survived until today. In this paper, “dark matter” is used to refer to the nonbaryonic matter, mostly located in large dark halos, that is, CDM in the standard paradigm, and “missing baryons” or “dark baryons” is used to refer to the baryons known to exist but hardly observed at redshift zero, and are a baryonic dark component that is additional to “dark matter”.

scholarly journals Vertical Motion and the Thickness of Hi Disks: Implications for Galactic Mass Models

1983 ◽  
Vol 100 ◽  
pp. 69-76
Author(s):  
P. C. van der Kruit ◽  
G. S. Shostak
Keyword(s):  
Dark Matter ◽  
Mass Distribution ◽  
Rotation Curve ◽  
Spiral Galaxies ◽  
Galactic Plane ◽  
Vertical Motion ◽  
Late Type ◽  
Rotation Curves ◽  
Central Bulge ◽  
Local Value

Most studies of the mass distribution in spiral galaxies have been based on the observed rotation curves. A serious ambiguity in this approach has always been that the rotation curve contains in itself no information on the mass distribution in the direction perpendicular to the galactic plane. The usual assumption has been that the mass in late type galaxies is distributed as the light, namely outside the central bulge in a highly flattened disk. In recent years it has been found that the rotation curves decline little or not at all, indicating large increases in the local value of M/L with increasing galactocentric radius (e.g. Bosma and van der Kruit, 1979). On the basis of dynamical arguments involving stability it has been suspected that the material giving rise to the large values of M/L - the “dark matter” - is distributed in the halos of these galaxies, so that the assumption of a flat mass distribution would have to be wrong.

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