Weijing Wu (Institute of Astronomy, National Central University, Taoyuan, Taiwan); Chorng-Yuan Hwang (Institute of Astronomy, National Central University, Taoyuan, Taiwan)
Dark matter was originally proposed to explain the flat rotation curves observed in spiral galaxies. So far it has also been found in elliptical galaxies and dwarf galaxies. Dwarf galaxies are numerous in the universe, but many of them are too faint to observe. In this study, we investigate the dark matter distributions of dwarf galaxies using the SDSS MaNGA data. Dwarf galaxies are defined to be galaxies with stellar mass smaller than 10^9 solar mass. The rotations of the galaxies are determined from their stellar velocity maps or gas velocity maps. For the galaxies with clear rotation patterns of gas velocity, we obtained the rotation curves using the code 3D BAROLO to analyze the fluxes of Hα. Combining the velocity dispersions, we could estimate the dynamical mass of these galaxies. For galaxies without rotation, we used velocity dispersion to estimate their dynamical mass. We also estimated the stellar mass distribution using the K-band data from 2MASS. By assuming the major mass components of dynamical mass are stars and dark matter, the distribution of dark matter could be obtained for our targets. We used three models (NFW, Soliton and Burkert profiles) to fit the distributions, which may shed some light on the nature of dark matter.