The universal rotation curve of spiral galaxies — I. The dark matter connection

Abstract

We use a homogeneous sample of about 1100 optical and radio rotation curves (RCs) and relative surface photometry to investigate the main mass structure properties of spirals, over a range of 6 magnitudes and out to ∼ < 1.5 and 2 optical radii (for the optical and radio data, respectively). We definitely confirm the strong dependence on luminosity for both the profile and the amplitude of RCs claimed by Persic & Salucci (1991). Spiral RCs show the striking feature that a single global parameter, e.g. luminosity, dictates the rotation velocity at any radius for any object, so unveiling the existence of a Universal RC. At high luminosities, there is a slight discrepancy between the profiles of RCs and those predicted from the luminous matter (LM) distributions: this implies a small, yet detectable, amount of dark matter (DM). At low luminosities, the failure of the LM prediction is much more severe, and the DM is the only relevant mass component. We show that the Universal RC implies a number of scaling properties between dark and luminous galactic structure parameters: (a) the DM/LM mass ratio scales inversely with luminosity; (b) the central halo density scales as L −0.7 ; (c) the halo core radius is comparable to the optical radius, but shrinks for low luminosities; (d) the total halo mass scales as L 0.5 . Such scaling properties can be represented as a curve in the (luminosity)-(DM/LM mass ratio)-(DM core radius)-(DM central density) space, which provides a geometrical description of the tight coupling between the dark and the luminous matter in spiral galaxies.

A Review on the Scalar Field/Bose-Einstein Condensate Dark Matter Model

“…Back then he used the virial theorem to obtain the average mass of galaxies within the Coma cluster and obtained a value much larger than the mass of the luminous material, he then realized that some mass was "missing" in order to account for observations. This missing mass problem was confirmed many years later by more accurate measurements of rotation curves of disc galaxies, [19,96,108,23]. The rotation curves of neutral hydrogen clouds in spiral galaxies measured by the Doppler effect are now found to be roughly flat with a typical rotation velocity equal to v ∞ ∼ 200km/s up to the maximum observed radius of about 50kpc.…”

Dark Matter 2017

“…The pure Newtonian dynamics of the rotation of the luminous matter indicates that gravity field is produced by a sphere of uniform density, and not by a self gravitating ensemble of non-collision particles [12]. A possible explanation of this fact could be the existence of a large mass of dark baryon in the inner part of the spiral galaxies [13], but alternatively it could be also the indication of self-interaction of the DM particles [14]. In the latter case the original "cuspy" halos could have been smoothed out, on a scale equal to the free streaming distance.…”

Outer Disk Star Formation in HI selected Galaxies

“…The driving property of the model -halo mass, is parameterized by the peak orbital velocity V max . The shape of the rotation curve for a given V max is taken from the pa-rameterization of Persic et al (1996). We use observed scaling relations to set the stellar mass distribution which we put in a pure exponential disk (Freeman 1970).…”