Deep photometry of globular clusters. III. The globular cluster in Eridanus GLC 0423-21.
Abstract
An analysis of the outer halo globular cluster GlC0423-21 in Eridanus is presented based on CCD and photographic material. It is found that GlC0423-21 is an intermediate metal-poor cluster in the outer halo. Its distance modulus is 19.5 + or 0.2 for a reddening of E(B-V) = 0.03. The distance is thus 79 + or - 8 kpc. A metal abundance of (Fe/H) = -1.5 + or - 0.3 is derived from the color of the giant branch at the horizontal branch level of (B-V)0,g = 0.79 + or - 0.06. The horizontal branch is extremely red; GlC0423-21 is thus an extreme case of the second parameter effect among outer halo clusters. The luminosity function of this cluster is statistically undistinguishable from that of M3, and is about 50 times less populous than M3. The absolute integrated magnitude is thus M(V,t) = -4.7 + or - 0.2, a low value comparable to other outer halo clusters. Adopting an M/L ratio of 1.6, a total mass of 8000 solar masses is derived.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- May 1986
- Bibcode:
- 1986A&A...160...25O
- Keywords:
-
- Globular Clusters;
- Stellar Spectrophotometry;
- Ubv Spectra;
- Charge Coupled Devices;
- Data Reduction;
- Error Analysis;
- Stellar Luminosity;
- Astrophysics