NFW Profile

The Navarro-Frenk-White (NFW) profile is the basic assumption for galactic phenomenology. It is used both, for matter, and dark matter, because so little is known about the 22% or so of the dark matter in the Universe. The Lambda-CDM model posits that there is a 74% part dark energy, 22% dark matter, and the rest, 4% the baryonic matter we are familiar with.

Recently Spolyar et al. published in Physical Review Letters a new model for the first stars formed after the Big Bang (See note above), they call these "dark stars". They claim that the annihilation of dark matter provided the energy that we may see as light with the successor of the Hubble Space Telescope, the so-called James Webb Space Telescope. They use the NVR profile to make their predictions. Since Carlos Frenk is Mexican, I want to acknowledge here the contribution of this gifted scientist.

You can read here a clear description of Prof. Frenk's computational work.

Spolyar et al. end their paper with this paragraph:

"What are other observational consequences of a “dark star”? If these objects are luminous but differ from ordinary stars (e.g. shine at lower temperatures), then James Webb Space Telescope could in principle find them (at z∼10) and differentiate their spectra from those expected in the standard first star formation scenarios. In addition, one might hope to detect the DM annihilation products such as neutrinos and γ-rays. However, the angular resolution of current and planned detectors (AMANDA, ICECUBE, GLAST, HESS, VERITAS, MAGIC) is not good enough to identify an individual dark star source at z > 10, so that the ν and γ s would add to the extragalactic backgrounds and could provide limits at best. Remnants today of the dark star phase would be more testable, such as stellar remnants still in enhanced DM distributions. Today’s remnant 10⁶ DM halos that were once the site of star formation may be modified due to the adiabatic contraction that took place earlier, so that enhanced DM annihilation might still occur today and these objects could be identified in upcoming experiments as individual ν or γ sources."