Planetary nebulae are important test particles for studying the halo dynamics and mass distributions in early-type galaxies. We review briefly the kinematical properties of the planetary-nebula system in the galaxy NGC 5128, the best studied case to date. By applying the spherical Jeans equation to the observed PN major axis rotation and velocity dispersion, we find that the mass-to-light ratio increases with radius, suggesting the presence of dark matter in the halo. The gas dynamics of the dust lane in the galaxy are consistent with this conclusion.
机构:
California Institute of Technology, Pasadena,CA,91125, United States
Department of Theoretical Physics, Keble Road, Oxford,OX1 3NP, United KingdomCalifornia Institute of Technology, Pasadena,CA,91125, United States
机构:
California Institute of Technology, Pasadena,CA,91125, United States
Department of Theoretical Physics, Keble Road, Oxford,OX1 3NP, United KingdomCalifornia Institute of Technology, Pasadena,CA,91125, United States