Comparative testing of dark matter models with 9 HSB and 9 LSB galaxies [GA]

http://arxiv.org/abs/1604.02465


We ensemble a database of 9 high-surface brightness (HSB) and 9 low-surface brightness (LSB) galaxies, for which both surface brightness density and spectroscopic rotation curve data are available in the literature, and are representative for the various morphologies. We use this dataset for a comparative testing of the Navarro-Frenk-White, the Einasto, and the pseudo-isothermal sphere dark matter models. We investigate the compatibility of the pure baryonic model and baryonic plus one of the three dark matter models with observations on the assembled galaxy database. When dark matter component is necessary to explain the spectroscopic rotational curves, we rank the models according to the goodness of fitting to the datasets. We construct the spatial luminosity density of the baryonic component based on the surface brightness profile of the galaxies. An axissymetric, baryonic mass model with variable axis ratios and three dark matter models are employed to fit the theoretical rotational velocity curves to the dataset. We perform $\chi^{2}$-tests to establish the relevance of dark matter models, and employ the Akaike information criterion to rank them. The statistical investigation suggests that in 7 cases out of 18 (for 5 HSB and 2 LSB galaxies) the addition of a dark matter component does not significantly improve the fit. In the rest of the cases the pseudo-isothermal sphere model is needed with the largest statistical significance for HSB galaxies, while for LSB galaxies the three dark matter models occur with similar significance.

Read this paper on arXiv…

E. Kun, G. Szucs, Z. Keresztes, et. al.
Tue, 12 Apr 16
55/63

Comments: 8 pages, 3 figures, 5 tables