%0 Journal Article
%T Slowly rotating Bose¨CEinstein condensate compared with the rotation curves of 12 dwarf galaxies
%A E. Kun
%A L. ¨¢. Gergely
%A Z. Keresztes
%J -
%D 2020
%R 10.1051/0004-6361/201936504
%X <i>Context.<i/> The high plateaus of the rotation curves of spiral galaxies suggest either that there is a dark component or that the Newtonian gravity requires modifications on galactic scales to explain the observations. We assemble a database of 12 dwarf galaxies, for which optical (<i>R<i/>-band) and near-infrared (3.6£¿<i>¦Ì<i/>m) surface brightness density together with spectroscopic rotation curve data are available, in order to test the slowly rotating Bose¨CEinstein condensate (BEC) dark matter model.<i>Aims.<i/> We aim to establish the angular velocity range compatible with observations, bounded from above by the requirement of finite-size halos, to check the model fits with the dataset, and the universality of the BEC halo parameter £¿.<i>Methods.<i/> We constructed the spatial luminosity density of the stellar component of the dwarf galaxies based on their 3.6£¿<i>¦Ì<i/>m and <i>R<i/>-band surface brightness profiles, assuming an axisymmetric baryonic mass distribution with arbitrary axis ratio. We built up the gaseous component of the mass by employing an inside-truncated disk model. We fitted a baryonic plus dark matter combined model, parametrized by the <i>M<i/>/<i>L<i/> ratios of the baryonic components and parameters of the slowly rotating BEC (the central density <i>¦Ñ<i/><sub>c<sub/>, size of the BEC halo £¿ in the static limit, angular velocity <i>¦Ø<i/>) to the rotation curve data.<i>Results.<i/> The 3.6£¿<i>¦Ì<i/>m surface brightness of six galaxies indicates the presence of a bulge and a disk component. The shape of the 3.6£¿<i>¦Ì<i/>m and <i>R<i/>-band spatial mass density profiles being similar is consistent with the stellar mass of the galaxies emerging wavelength-independent. The slowly rotating BEC model fits the rotation curve of 11 galaxies out of 12 within the 1<i>¦Ò<i/> significance level, with the average of £¿ as 7.51 kpc and standard deviation of 2.96 kpc. This represents an improvement over the static BEC model fits, also discussed. For the 11 best-fitting galaxies the angular velocities allowing for a finite-size slowly rotating BEC halo are less then 2.2£¿¡Á£¿10<sup>£¿16<sup/> s<sup>£¿1<sup/>.For a scattering length of the BEC particle of <i>a<i/>£¿¡Ö£¿10<sup>6<sup/> fm, as allowed by terrestrial laboratory experiments, the mass of the BEC particle is slightly better constrained than in the static case as <i>m<i/>£¿¡Ê£¿[1.26£¿¡Á£¿10<sup>£¿17<sup/>£¿¡Â£¿3.08£¿¡Á£¿10<sup>£¿17<sup/>] (eV c<sup>£¿2<sup/>)
%U https://www.aanda.org/articles/aa/full_html/2020/01/aa36504-19/aa36504-19.html