Bose-Einstein Condensate Dark Matter Halos confronted with galactic observations

We present a comparative confrontation of both the Bose-Einstein Condensate (BEC) and the Navarro-Frenk-White (NFW) dark halo models with galactic rotation curves and velocity dispersion data. We conclude that the BEC model fits better the dwarf galaxy dark matter distribution, but suffers from sharp cut-off in larger galaxies, where the NFW model performs better. In more detail, we employ 6 High Surface Brightness (HSB), 6 Low Surface Brightness (LSB) and 7 dwarf galaxies with rotation curves falling into two classes, based on their shapes. In the first class the rotational velocities increase with radius over the whole observed range, the BEC and NFW models giving comparable fits for both HSB and LSB galaxies, while significantly improving over the NFW fit for dwarf galaxies. This improvement is due to the central density cusp avoidance property of the BEC model. The rotational velocity of HSB and LSB galaxies falling into the second class exhibit long flat plateaus, resulting in a better fit of the NFW model for HSB galaxies, and comparable fits for LSB galaxies. The weaker performance of the BEC model for the HSB type II galaxies is due to the BEC density profiles dropping rapidly to zero outside a nearly constant density core. Finally we confront both models with the projected velocity dispersion profiles of 6 Virgo cluster galaxies, which after a steep rising, remain flat over the sampled region. The two models gave comparable combined $\tilde{\chi}_{\min}^{2}$ values for these galaxies but both model fits remained outside the 3$\sigma$ confidence level, pointing out the need for a better modelling of the velocity dispersion of galaxies that both the BEC and NFW models could provide.