Physical Sciences and Technology (Dec 2020)
Physical properties of dark matter in galaxy U11454
Abstract
In this paper physical characteristics of dark matter distribution in the spiral galaxy U11454 is exploredusing only well-known cored density profiles in the literature such as the pseudo-isothermal, Burkert,Einasto, exponential sphere, Beta and Brownstein profiles. It is presumed that the distribution of darkmatter in the considered galaxy is spherically symmetric without taking into account its complexstructural components. It is assumed that dark matter possesses non-vanishing pressure which allowstheoretically analyzing the state parameter. The model free parameters of each profile are inferred fromthe rotation curve data of the galaxy by means of non-linear model fit procedure. Using the BayesianInformation Criterion the best fit profile among the considered ones is selected. Furthermore, thehydrostatic equilibrium equation is solved and the pressure profiles for each above mentioned densityprofile are constructed in the weak gravitational field regime. Combining the pressure and correspondingdensity profiles one gains equations of state for the dark matter in the galaxy U11454. The mass andgravitational potential are evaluated and constructed as a function of the radial distance for each profile.The total dark matter mass is assessed and our results are confronted and contrasted with the previousoutcomes. In addition, the speed of sound is estimated in the dark matter distribution and it is shown thatits behavior is quite unusual especially for the Brownstein profile. Finally, the refracting index iscalculated in order to assess gravitational lensing effects produced
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