Velocity dispersions and mass-to-light ratios for 9 globular clusters in M 31.
Abstract
We present internal velocity dispersion determinations from high-resolution spectroscopic observations of a sample of nine globular clusters in M 31. Comprehensive numerical simulations are used to show that the typical uncertainty of our velocity dispersion measurements is ~5%. Using these new velocity dispersions together with structural parameters derived from HST observations, we estimate the M/L_V_ ratios of these clusters and find that they are typical of those measured for Galactic clusters. We show relations between velocity dispersion, luminosity and physical scales for globular clusters belonging to the Galaxy, the Magellanic clouds, Fornax, M 31, and Centaurus A. The mean relations and the degree of scatter are similar in all galaxies. This reveals remarkable similarities, in term of structure and M/L_V_ ratio, between the globular clusters belonging to these different galaxies. We briefly discuss the possible use of individual globular clusters as extragalactic distance indicators.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- May 1997
- DOI:
- 10.48550/arXiv.astro-ph/9610194
- arXiv:
- arXiv:astro-ph/9610194
- Bibcode:
- 1997A&A...321..379D
- Keywords:
-
- GALAXIES: INDIVIDUAL: M 31;
- GALAXIES: STAR CLUSTERS;
- GALAXIES: HALOS;
- STARS: KINEMATICS;
- TECHNIQUES: RADIAL VELOCITIES;
- Astrophysics
- E-Print:
- LaTeX, 10 pages, 5 Postscript figures, uses l-aa.sty and epsf.sty. Accepted for publication in A&