FURTHER LIMITS ON DISKLIKE DARK MATTER FROM K-DWARF KINEMATICS

We present a sequence of model distribution functions with which the vertical motions of nonisothermal stellar disk populations in the solar neighborhood can be modeled. In particular, constraints can be placed on the gravitational potential and the amount of dark matter in a disklike component. Using the observed kinematics of K dwarf stars in the solar vicinity combined with the falloff in space density away from the Galactic midplane, we show that there is no evidence for a mass discrepancy within approximately 160 pc of the Galactic plane. This finding complements our earlier result that the local disk surface density of the Galaxy is also consistent with an absence of dark matter in a disklike distribution in the solar neighborhood.