Related papers: Flat Circular Velocities on a megaparsec scale fro…
The recent measurements of circular velocity curves from weak lensing of the isolated galaxies lead to a conclusion that the circular velocity curves remain flat well beyond the virial radii of dark matter halos up to 1 Mpc. This is in…
Mass models of a sample of 171 low- and high-surface brightness galaxies are presented in the context of the cold dark matter (CDM) theory using the NFW dark matter halo density distribution to extract a new concentration-viral mass…
Observations show that the underlying rotation curves at intermediate radii in spiral and low-surface brightness galaxies are nearly universal. Further, in these same galaxies, the product of the central density and the core radius…
We use a new deprojection formula to infer the gravitational potential around isolated galaxies from weak gravitational lensing. The results imply circular velocity curves that remain flat for hundreds of kpc, greatly extending the classic…
Recent observations by Mistele et al. show that the circular velocity curves of isolated galaxies remain flat out to the largest radii probed so far, i.e. $\approx 1$ Mpc. The velocity decline beyond the expected virial radius is not…
We use the rotation curves of more than 100 disk galaxies to examine whether the structure of their surrounding dark halos is consistent with the universal density profile proposed by Navarro, Frenk & White (NFW profiles). Rotation curve…
We address the issue of accuracy in recovering density profiles from observations of rotation curves of galaxies. We ``observe'' and analyze our models in much the same way as observers do the real galaxies. We find that the tilted ring…
Recent Strong lensing data and rotation curves of dwarf galaxies indicate that many galactic clusters may have a soft core instead of a central cusp in their density distribution. This result challenges the standard CDM (Cold Dark Matter)…
The shape and diversity of dwarf galaxy rotation curves is at apparent odds with dark matter halos in a $\Lambda$ Cold Dark Matter ($\Lambda$CDM) cosmology. We use mock data from isolated dwarf galaxy simulations to show that this owes to…
We present high-resolution optical velocity fields from DensePak integral field spectroscopy, along with derived rotation curves, for a sample of low surface brightness galaxies. In the limit of no baryons, we fit the NFW and…
Rotation curves of dark-matter-dominated galaxies measure the mass profiles of galactic halos and thereby test theories of their cosmological origin. While attention has focused lately on the possible discrepancy at small galactocentric…
Weak lensing exhibits that rotation curves of isolated galaxies remain flat up to Mpc scale (Mistele et al, 2024). Recently we proposed that dark matter is a combination of electrostatic and vacuum energy in standard physics. In this…
A mysterious dark matter is supposed to exist in the galactic halos. In this contrast, we discuss the possibility of explaining the flat rotational velocity curves in f(R) gravity by solving field equations numerically in vacuum and for…
Aims. We present an analysis of 37 high-quality extended rotation curves that highlights the existence of a new discrepancy (or a new aspect of an old discrepancy) between the density profiles predicted by the Lambda Cold Dark Matter…
The rotation curves of spiral galaxies exhibit a diversity that has been difficult to understand in the cold dark matter (CDM) paradigm. We show that the self-interacting dark matter (SIDM) model provides excellent fits to the rotation…
In cosmological N-body simulations, the baryon effects on the cold dark matter (CDM) halos can be used to solve the small scale problems in $\Lambda$CDM cosmology, such as cusp-core problem and missing satellites problem. It turns out that…
A cylindrical model for the dark matter halo of disk galaxies is developed. At the center of the cylinder, in the plane perpendicular to the long axis, the rotation curve is constant for distances much less than the cylinder length and…
We present mass models for a sample of 30 high-resolution rotation curves of low surface brightness (LSB) galaxies. We fit both pseudo-isothermal (core-dominated) and Cold Dark Matter (CDM) (cusp-dominated) halos for a wide variety of…
We conducted an analysis of the velocity field of dwarf galaxies in the LITTLE THINGS sample, focusing on deriving 2D velocity maps that encompass both the transverse and radial velocity fields. Within the range of radial distances where…
The rich statistics of galaxy rotations as captured by the velocity function (VF) provides invaluable constraints on galactic baryon physics and the nature of dark matter (DM). However, the comparison of observed galaxy rotations against…