Speaker
Description
Dark matter content within a few Re of galaxies can provide important test of hydrodynamical cosmological simulations, but we are still lacking of reliable measurements of dark matter content in a large number of galaxies across the Hubble types. IFU surveys have provide stellar kinematics for thousands of nearby galaxies, but they usually only cover the inner 1-2Re of galaxies. To strongly constrain the dark matter mass, we need kinematic tracers at the outer regions of galaxy. In this talk, I will introduce a new method combining stellar kinematics from IFU observations and integrated HI spectrum. Although with no spatial resolution of the HI gas kinematics, we can constrain the dark matter fraction within 5Re with a relative uncertainty of ~40%, which is significantly reduced comparing to the uncertainty of ~100% with IFU only. Such integrated HI spectrum can be obtained efficiently for large sample of nearby galaxies from such as HI-MaNGA survey and FAST observations. This will allow us to constrain dark matter content accurately in a large sample of nearby galaxies.
