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Globular cluster ages: are they converging?

Published online by Cambridge University Press:  25 May 2016

Don A. VandenBerg*
Affiliation:
Dept. of Physics & Astronomy, University of Victoria P.O. Box 3055, Victoria, B.C., Canada V8W 3P6

Abstract

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Since the early 1970's, the consensus “best estimate” of the age of the Galactic globular cluster (GC) system has been 15–16 ±3 Gyr. However, a number of recent studies, which are briefly reviewed herein, have suggested that this estimate is too high by ≳ 15%. Based on a consideration of new stellar models and the latest developments concerning the cluster distance scale, the present paper lends support to the notion that the first globulars began to form in the Galaxy 13–14 Gyr ago. In addition, our analysis of absolute GC ages adds to the mounting evidence that the dispersion in age among clusters having similar metallicities is probably quite small. As a consequence, age can hardly be the primary factor causing the wide diversity in their horizontal-branch morphologies.

Type
Stellar Ages
Copyright
Copyright © Kluwer 1997 

References

Bahcall, J.N. & Pinsonneault, M.H. 1992, Rev. Mod. Phys. , 64, 885 Google Scholar
Bell, R.A. 1996, private communication Google Scholar
Bolte, M. 1994, Ap. J. , 431, 223 Google Scholar
Bolte, M. 1997, private communication Google Scholar
Brown, J.A., Wallerstein, G., & Oke, J.B. 1990, A.J. , 100, 1561 Google Scholar
Buser, R. & Kurucz, R.L. 1978, Astron. Astrophys. , 70, 555 (BK78) Google Scholar
Buser, R. & Kurucz, R.L. 1992, Astron. Astrophys. , 264, 557 (BK92) Google Scholar
Caloi, V., Castellani, V., Danziger, J., et al. 1986, M.N.R.A.S. , 222, 55 Google Scholar
Canuto, V.M. & Mazzitelli, I. 1991, Ap. J. , 370, 295 Google Scholar
Carney, B.W. 1996, P.A.S.P. , 108, 900 Google Scholar
Carney, B.W., Storm, J., & Jones, R.V. 1992, Ap. J. , 386, 663 Google Scholar
Chaboyer, B., Demarque, P., Kernan, P.J., & Krauss, L.M. 1996a, Science , 271, 957 Google Scholar
Chaboyer, B., Demarque, P., Kernan, P.J., et al. 1996b, M.N.R.A.S. , 283, 683 Google Scholar
Chaboyer, B., Demarque, P., & Sarajedini, A. 1996c, Ap.J. , 459, 558 (CDS96) Google Scholar
D'Antona, F., Caloi, V., & Mazzitelli, I. 1997, Astron. Astrophys. , in press Google Scholar
Dorman, B., VandenBerg, D.A., & Laskarides, P.G. 1989, Ap.J. , 343, 750 Google Scholar
Ferraro, F.R., Paltrinieri, B., Fusi Pecci, F., et al. 1997, Ap. J. Lett. , submitted Google Scholar
Fusi Pecci, F., Buonanno, R., Cacciari, C., et al. 1996, A.J. , 112, 1461 CrossRefGoogle Scholar
Hesser, J.E., Harris, W.E., VandenBerg, D.A., et al. 1987, P.A.S.P. , 99, 739 Google Scholar
Jimenez, R. & Padoan, P. 1996, Ap. J. Lett. , 463, L17 Google Scholar
Jimenez, R., Thejll, P., Jorgensen, U.G., MacDonald, J., & Pagel, B. 1996, M.N.R.A.S. , 282, 926 (JTJMP) CrossRefGoogle Scholar
Johnson, J. & Bolte, M. 1997, in preparation Google Scholar
Kurucz, R.L. 1992, Solar Abundance Model Atmospheres (CD-ROM 19) Google Scholar
Lee, Y.-W. 1990, Ap.J. , 363, 159 CrossRefGoogle Scholar
Mazzitelli, I., D'Antona, F., & Caloi, V. 1995, Astron. Astrophys. , 302, 382 Google Scholar
McClure, R.D., VandenBerg, D.A., Bell, R.A., et al. 1987, A.J. , 93, 1144 CrossRefGoogle Scholar
Penny, A.J. & Dickens, R.J. 1986, M.N.R.A.S. , 220, 845 Google Scholar
Reimers, D. 1975, Mem. Soc. Roy. Sci. Liège , 8, 369 Google Scholar
Renzini, A., Bragaglia, A., Ferraro, F.R., et al. 1996, Ap. J. Lett , 465, L23 Google Scholar
Richer, H.B., Harris, W.E., Fahlman, G.G., et al. 1996, Ap. J. , 463, 602 Google Scholar
Rogers, F.J. & Iglesias, C.A. 1992, Ap. J. Suppl. , 79, 507 Google Scholar
Ryan, S.G., Norris, J.E., & Beers, T.C. 1996, Ap.J. , 471, 254 Google Scholar
Salaris, M., Degl'Innocenti, S., & Weiss, A. 1996, preprint Google Scholar
Stetson, P.B. & Harris, W.E. 1988, A.J. , 96, 909 Google Scholar
Stetson, P.B., VandenBerg, D.A., & Bolte, M. 1996, P.A.S.P. , 108, 560 CrossRefGoogle Scholar
Tornambé, A. 1987, in ESO Workshop on Stellar Evolution and Dynamics in the Outer Halo of the Galaxy , ed. Azzopardi, M. & Matteucci, F. (Garching: ESO), p. 307 Google Scholar
VandenBerg, D.A. 1997a, in Advances in Stellar Evolution , ed. Rood, R.T. & Renzini, A. (Cambridge: Cambridge U. Press), in press Google Scholar
VandenBerg, D.A. 1997b, in preparation Google Scholar
VandenBerg, D.A. & Bell, R.A. 1985, Ap. J. Suppl , 58, 561 (VB85) Google Scholar
VandenBerg, D.A., Bolte, M., & Stetson, P.B. 1990, A.J. , 100, 445 (VBS90) Google Scholar
VandenBerg, D.A., Bolte, M., & Stetson, P.B. 1996, Ann. Rev. Astron. Astrophys. , 34, 461 (VBS96) Google Scholar
VandenBerg, D.A., Swenson, F.J., Rogers, F.J., Iglesias, C.A., & Alexander, D.R. 1997, in preparation Google Scholar
Walker, A.R. 1994, A.J. , 108, 555 Google Scholar