Friday, January 20, 2012

1201.3998 (Gianluca Castignani et al.)

The density profiles of Dark Matter halos in Spiral Galaxies    [PDF]

Gianluca Castignani, Noemi Frusciante, Daniele Vernieri, Paolo Salucci
In spiral galaxies, we explain their non-Keplerian rotation curves (RCs) by means of a non-luminous component embedding the stellar-gaseous disks. Understanding the detailed properties of this component (labelled Dark Matter, DM) is one of the most pressing issues of Cosmology. We investigate the recent relationship (claimed by Walker et al. 2010) between $r $, the galaxy radial coordinate, and the dark halo contribution to the circular velocity at $r$, {\it a}) in the framework of the Universal Rotation Curve (URC) paradigm and directly {\it b}) by means of the kinematics of a large sample of Dark matter dominated spirals. We find a general agreement between the W+10 claim, the distribution of DM emerging from URC and that inferred in the (low luminosity) objects. We show that the emerging phenomenology, linking the spiral's luminosity, radii and circular velocities, implies an evident inconsistency with (naive) predictions in the $\Lambda$CDM scenario.
View original: http://arxiv.org/abs/1201.3998

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