The mass distribution in the galactic disc -III. The local volume mass density.
Abstract
Evidence for missing mass associated with the galactic disc is usually derived from solutions of the combined Poisson and Boltzmann equations which describe the velocity dispersion and density data for samples of F dwarfs and K giants near the Sun. Previous analyses have deduced that perhaps 50 per cent of the local volume mass density is not identified with known stars or with the interstellar medium. We show here that some of the data on which such conclusions were based are internally inconsistent. Similarly the velocity models previously applied to analyse the remaining data are not consistent with the observed age-velocity dispersion relations near the Sun, and with stellar evolutionary tracks. Reanalysis of the available F dwarf and K giant data with more plausible models provides no evidence for any missing matter near the Sun in addition to the identified ρo,id = 0.10 Msunpc-3.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- August 1989
- DOI:
- 10.1093/mnras/239.2.651
- Bibcode:
- 1989MNRAS.239..651K