Constraining the Magnetic Effects on H I Rotation Curves and the Need for Dark Halos

@article{SnchezSalcedo2004ConstrainingTM,
  title={Constraining the Magnetic Effects on H I Rotation Curves and the Need for Dark Halos},
  author={F. Javier S{\'a}nchez-Salcedo and Mauricio Reyes-Ruiz},
  journal={The Astrophysical Journal},
  year={2004},
  volume={607},
  pages={247-257}
}
The density profiles of dark halos are usually inferred from the rotation curves of disk galaxies based on the assumption that the gas is a good tracer of the gravitational potential of the galaxies. Some authors have suggested that magnetic pinching forces could alter significantly the rotation curves of spiral galaxies. In contrast to other studies that have concentrated on the vertical structure of the disk, here we focus on the problem of magnetic confinement in the radial direction to… Expand
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References

SHOWING 1-10 OF 53 REFERENCES
On the role of magnetic fields in H I rotation curves
The importance of large-scale magnetic fields in H I rotation curves of spiral galaxies is investigated. In contrast to other papers that try to render dark matter unnecessary, we assume thatExpand
The Structure of cold dark matter halos
High resolution N-body simulations show that the density profiles of dark matter halos formed in the standard CDM cosmogony can be fit accurately by scaling a simple “universal” profile. RegardlessExpand
Magnetic fields as an alternative explanation for the rotation curves of spiral galaxies
THE flat rotation curves of spiral galaxies are usually regarded as the most convincing evidence for dark matter. The assumption that gravity alone is responsible for the motion of gas beyond theExpand
The Evolution of a Primordial Galactic Magnetic Field
We consider the hypothesis that galactic magnetic fields are primordial. We also discuss the various objections to this hypothesis. To test this hypothesis properly we assume that there was aExpand
Simulating observations of dark matter dominated galaxies: towards the optimal halo profile
Low surface brightness galaxies are dominated by dark matter, and their rotation curves thus reflect their dark matter distribution. Recent high-resolution rotation curves suggest that their darkExpand
Neutral Hydrogen in the Outer Galaxy
The H I 21 cm emission-line survey data of Stark et al. (1991) have been used to study the distribution of H I in the outer Galaxy and to improve understanding of the various systematic problemsExpand
Where Do the Disks of Spiral Galaxies End
In spiral galaxies, the H I surface density declines with increasing radius to a point at which it is seen to truncate dramatically in the best observed cases. If the ambient radiation field isExpand
The Density Profile of the Dark Matter Halo of NGC 4605
We have obtained ~100 pc resolution CO and ~60 pc resolution Halpha observations of the dwarf spiral galaxy NGC 4605. We use them to derive a high resolution rotation curve and study the centralExpand
At the low-mass end - Light and H I distribution of GR 8
The dwarf irregular galaxy GR 8, which is at the extreme faint end of the luminosity and mass functions, is studied using optical photometry and 21 cm H I line observations. For the lightExpand
The angular momentum content of dwarf galaxies: new challenges for the theory of galaxy formation
We compute the specific angular momentum distributions for a sample of low-mass disc galaxies observed by Swaters. We compare these distributions to those of dark matter haloes obtained by Bullock etExpand
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2
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4
5
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