Unexpected interaction between dark matter and ordinary matter in mini-spiral galaxies December 15, 2016 Please Register or Log in to view the hidden image! Credit: ESO’s OmegaCAM on the VLT Survey Telescope Statistical analysis of mini-spiral galaxies shows an unexpected interaction between dark matter and ordinary matter. According to the SISSA study recently published in Monthly Notices of the Royal Astronomical Society, where the relationship is obvious and cannot be explained in a trivial way within the context of the Standard Model, these objects may serve as "portals" to a completely new form of Physics which can explain phenomena like matter and dark energy. They resemble a spiral galaxy like ours, only ten thousand times smaller: the mini-spiral galaxies studied by Professor Paolo Salucci of the International School for Advanced Studies (SISSA) in Trieste, and Ekaterina Karukes, who recently earned her PhD at SISSA, may prove to be "the portal that leads us to a whole new Physics, going beyond the standard model of particles to explain matter and dark energy," says Salucci. It is the first time these elements have been studied statistically, a method that can erase the "individual" variability of each object, thus revealing the general characteristics of the class. "We studied 36 galaxies, which was a sufficient number for statistical study. By doing this, we found a link between the structure of ordinary, or luminous matter like stars, dust and gas, with dark matter." Read more at: http://phys.org/news/2016-12-unexpected-interaction-dark-ordinary-mini-spiral.html#jCp
http://mnras.oxfordjournals.org/content/early/2016/11/29/mnras.stw3055 The universal rotation curve of dwarf disk galaxies: Abstract We use the concept of the spiral rotation curves universality (see Persic et al. 1996) to investigate the luminous and dark matter properties of the dwarf disk galaxies in the local volume (size ∼11 Mpc). Our sample includes 36 objects with rotation curves carefully selected from the literature. We find that, despite the large variations of our sample in luminosities (∼ 2 of dex), the rotation curves in specifically normalized units, look all alike and lead to the lower-mass version of the universal rotation curve of spiral galaxies found in Persic et al. (1996). We mass model the double normalized universal rotation curve V(R/Ropt)/Vopt of dwarf disk galaxies: the results show that these systems are totally dominated by dark matter whose density shows a core size between 2 and 3 stellar disk scale lengths. Similar to galaxies of different Hubble types and luminosities, the core radius r0 and the central density ρ0 of the dark matter halo of these objects are related by ρ0r0 ∼ 100M⊙pc−2. The structural properties of the dark and luminous matter emerge very well correlated. In addition, to describe these relations, we need to introduce a new parameter, measuring the compactness of light distribution of a (dwarf) disk galaxy. These structural properties also indicate that there is no evidence of abrupt decline at the faint end of the baryonic to halo mass relation. Finally, we find that the distributions of the stellar disk and its dark matter halo are closely related.
