A study of the galactic halo from a complete sample of RR Lyrae variables to B = 21.
Abstract
An automated search of a sequence of 1.2-m Schmidt plates is used to obtain a complete sample of RR Lyrae variables to B = 21. The sample is used to trace the space density of the halo to 60 kpc. A power-law distribution with index -3.1±0.2 is found, with an axial ratio of about 0.9. Radial velocities of sample members as a function of Galactocentric distance give a power-law relation with index -0.7±0.4 for the overall mass density; this is different from the distribution of the variables themselves and apparently shows the distribution of unseen matter.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- January 1984
- DOI:
- 10.1093/mnras/206.3.433
- Bibcode:
- 1984MNRAS.206..433H
- Keywords:
-
- Cepheid Variables;
- Halos;
- Space Density;
- Stellar Spectrophotometry;
- Stellar Structure;
- Galactic Nuclei;
- Radial Velocity;
- Star Distribution;
- Astrophysics