Large Scale Photographic Survey of Fornax
Abstract
Two pairs of CTIO 4 m prime-focus plates, measured by the APM, are used to investigate the structure of Fornax and its globular clusters. The surface distribution of stars reveals that the inner isopleths of Fornax are asymmetric. The position of highest density corresponds to cluster 4,3' off from the geometrical center. Core and tidal radii (r_c_,r_t_) are determined for the five globular clusters and for Fornax itself. Estimates of the r_c_, r_t_ for Fornax confirm the recent results of Irwin & Hatzidimitriou [ASP Conf. Ser., 48,322(1993)]. A global color- magnitude diagram reveals a well defined red clump and a weak blue horizontal branch. The oldest stars represent barely 4% of the Fornax populations. There is a slight indication that these older stars are more concentrated near the center than the bulk of Fornax. The age of the bulk of Fornax is found to be ~2 Gyr when applying the d_B-R_ parameter of Hatzidimitriou [MNRAS, 251, 545 (1991)]. From a comparison of the number of giants in Fornax and in M3 we derive a Mnu_ = - 13.1 for Fornax.
- Publication:
-
The Astronomical Journal
- Pub Date:
- November 1994
- DOI:
- Bibcode:
- 1994AJ....108.1648D
- Keywords:
-
- Astronomical Photography;
- Dwarf Galaxies;
- Giant Stars;
- Globular Clusters;
- Horizontal Branch Stars;
- Sky Surveys (Astronomy);
- Star Distribution;
- Stellar Spectrophotometry;
- Color-Magnitude Diagram;
- Stellar Luminosity;
- Astronomy;
- GALAXIES: PECULIAR;
- GALAXIES: INDIVIDUAL: FORNAX;
- GALAXIES: STELLAR CONTENT