2 research outputs found
Are dwarf spheroidal galaxies dark matter dominated or remnants of disrupted larger satellite galaxies? -- A possible test
The failure of standard cosmolocical models in accounting for the statistics
of dwarf satellites and the rotation curve of gas-rich dwarf galaxies in detail
has led us to examine whether earlier non-equilibrium models of dwarf
spheroidal satellites without any dark matter should be reconsidered in more
detail. Such models can explain the high dispersion of the dwarf spheroids by
the projection of disrupted tidal debris. We show in the case of Milky Way
satellites, that these models predict a significant spread in the apparent
magnitude of horizontal branch stars which is correlated with sky position and
velocity. In particular, the models produce a strong correlation of radial
velocity with the long axis of the dwarf. Current data do not set strong enough
constraints on the models, but we suggest that photometric and spectroscopic
surveys of extra-tidal stars of nearby dwarf spheroids in the Milky Way and
Andromeda can falsify these models without dark matter.Comment: 7 pages, 5 figures, accepted for publication in Ap