Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-28T22:32:15.447Z Has data issue: false hasContentIssue false

The Globular Cluster Terzan 7 in the Sagittarius Dwarf Spheroidal Galaxy

Published online by Cambridge University Press:  03 August 2017

Enrico V. Held
Affiliation:
Osservatorio Astronomico di Padova, I-35122 Padova, Italy
Alfred Rosenberg
Affiliation:
Instituto de Astrofísica de Canarias, 38200 La Laguna, Spain
Ivo Saviane
Affiliation:
European Southern Observatory, Casilla 19001, Santiago 19, Chile
Yazan Momany
Affiliation:
Dipartimento di Astronomia, Univ. di Padova, I-35122 Padova, Italy

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We present deep V, I photometry of the globular cluster Terzan 7, a probable member of the globular cluster system of the Sagittarius dwarf spheroidal galaxy. The metallicity, estimated from a new method based on analytic RGB fits, agrees with previous estimates based on color-magnitude diagrams ([Fe/H]= −0.9 ± 0.1 dex). This result confirms a discrepancy between photometric and spectroscopic determinations. Using both the horizontal and vertical methods to estimate relative ages, we confirm that the age of Terzan 7 is about 70% that of 47 Tuc. A rich population of blue stragglers is found, strongly concentrated toward the center of the cluster.

Type
Part 1. The Star Clusters of Local Group Galaxies
Copyright
Copyright © Astronomical Society of the Pacific 2002 

References

Buonanno, R., Corsi, C. E., Pulone, L., Fusi-Pecci, F., Richer, H. B., & Fahlman, G. C. 1995, AJ, 109, 663 CrossRefGoogle Scholar
Da Costa, G. S., & Armandroff, T. E. 1995, AJ, 109, 2533 Google Scholar
Dinescu, D. I., Majewski, S. R., Girard, T. M., & Cudworth, K. M. 2000, AJ, 120, 1892 Google Scholar
Hartwick, F. D. A. 1968, ApJ, 154, 475 Google Scholar
Ibata, R. A., Gilmore, G., Irwin, M. J. 1994, Nature, 370, 194 CrossRefGoogle Scholar
Landolt, A. U. 1992, AJ, 104, 340 CrossRefGoogle Scholar
Rosenberg, A., Saviane, I., Piotto, G., & Held, E. V. 1998, A&A, 339, 61 Google Scholar
Rosenberg, A., Piotto, G., Saviane, I., & Aparicio, A. 2000, A&AS, 144, 5 Google Scholar
Sarajedini, A., & Layden, A. 1997, AJ, 113, 264 Google Scholar
Saviane, I., Rosenberg, A., Piotto, G., & Aparicio, A. 2000, A&A, 355, 966 Google Scholar
Stetson, P. B., & Harris, W. E. 1988, AJ, 96, 909 CrossRefGoogle Scholar
Zinn, R., & West, M. J. 1984, ApJS, 55, 45 Google Scholar