Dark Matter Interactions in Spiral Dwarf Galaxies Analyzed

by Tommy on 15/12/2016

I win. Again. I suppose I had better get going on my gravitational axion essay now.



The universal rotation curve of dwarf disk galaxies, E.V. Karukes and P. Salucci, Monthly Notices of the Royal Astronomical Society, MNRAS, 464, 3, January 21, 2017 (29 November 2016), DOI:10.1093/mnras/stw3055

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 ∼ 100 Mpc−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.

‘The tip of the iceberg’. Welcome to my post-big-bang world of condensed matter physics.


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