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Revista mexicana de astronomía y astrofísica
versão impressa ISSN 0185-1101
Rev. mex. astron. astrofis vol.41 no.2 Ciudad de México Out. 2005
CCD photometry of M92
A. Ruelas-Mayorga and L. J. Sánchez
Instituto de Astronomía, UNAM, Apdo. Postal 70-264, 04510 México D. F., México (rarm@astroscu.unam.mx, leonardo@astroscu.unam.mx).
Received 2005 June 3
Accepted 2005 August 15
RESUMEN
Se presenta fotometría de Johnson en los filtros B y V para el cúmulo globular galáctico M92 (NGC 6341). Se obtuvieron resultados fotométricos para un total de ~ 30,000 estrellas las cuales se grafican en un diagrama V versus (B V). Se ajustaron isócronas teóricas a este diagrama para obtener una estimación de la edad de M92. La edad que encontramos es ~ 16 x 109 años con los siguientes valores para la metalicidad y la abundancia de Helio: [Fe/H] = 2.03, Y = 0.235. El módulo de distancia al cúmulo resulta ser de m M = 14.6 de acuerdo con el encontrado por Stetson & Harris (1988). También llevamos a cabo conteos estelares para producir una función de luminosidad, la cual se ajusta en forma exitosa con los modelos teóricos usados para el diagrama color-magnitud.
ABSTRACT
We present Johnson B and V photometry for the galactic globular cluster M92 (NGC 6341). Photometric results for a total of ~ 30,000 stars are obtained and are plotted on a V versus (B V) diagram. We fit theoretical isochrones to this diagram in order to get an estimate for the age of M92. The age which we find is ~ 16 x 109 years with the following values for the metallicity and He-abundance: [Fe/H] = 2.03, Y = 0.235. The distance modulus to this cluster turns out to be m M = 14.6 in accordance with that obtained by Stetson & Harris (1988). We also perform stellar counts in order to produce a luminosity function which is successfully fitted by the same theoretical models fitted to the colour-magnitude diagram.
Key Words: Galaxy: Halo Globular clusters: Individual (NGC 6341) Techniques: Photometric.
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REFERENCES
Alcaino, G. 1977, PASP, 89, 491 [ Links ]
Alcaino, G. & Liller, W. 1980, AJ, 85, 1330 [ Links ]
Andreuzzi, G., Buonanno, R., Fusi Pecci, F., Iannicola, G., & Marconi, G. 2000, A&A, 353, 944 [ Links ]
Bergbusch, P. A. 1990, AJ, 100, 182 [ Links ]
Bergbusch, P. A., & VandenBerg, D. A. 1992, ApJS, 81, 163 [ Links ]
----------. 2001, ApJ, 556, 322 [ Links ]
Bodenheimer, P. 1996, private communication [ Links ]
Boesgaard, A. M., & Steigman, G. 1985, ARA&A, 23, 319 [ Links ]
Bolte, M. 1987, ApJ, 319, 760 [ Links ]
----------. 1996, private communication [ Links ]
Bolte, M., & Hogan, P. 1995, Nature, 376, 399 [ Links ]
Burstein, D., & Heiles, C. 1982, AJ, 87, 1165 [ Links ]
Buzzoni, A., Pecci, F. F., Buonanno, R., & Corsi, C. E. 1983, A&A, 128, 94 [ Links ]
Carney, B. W. 1979a, ApJ, 233, 211 [ Links ]
----------. 1979b, ApJ, 233, 287 [ Links ]
Cathey, L. R. 1974, AJ, 79 1370 [ Links ]
Fahlman, G. G. 1993, in ASP Conf. Ser. Vol. 48, The Globular Cluster-Galaxy Connection, eds. G. H. Smith & J. P. Brodie (San Francisco: ASP), 117 [ Links ]
Fernley, J. 1993, A&A, 268, 591 [ Links ]
Freeman, K. C., & Norris, J. 1981, ARA&A, 19, 319 [ Links ]
Grundahl, F., VandenBerg, D. A., Bell, R. A., Andersen, M. I., & Stetson, P. B. 2000, AJ, 120, 1884 [ Links ]
Hanes, D., & Madore, B. F. 1980, in Globular Clusters (Cambridge: CUP) [ Links ]
Harris, W., & Racine, R. 1979, ARA&A, 17, 241 [ Links ]
Hartwick, F. D. A. 1970, ApJ, 161, 845 [ Links ]
Iben, I., & Rood, R. T. 1969, Nature, 223, 933 [ Links ]
Izotov, Y. I., & Thuan, T. X. 2004, ApJ, 602, 200 [ Links ]
Johnson, J.A., & Bolte, M. 1998, A&AS, 193, 2203 [ Links ]
Lee, J., Carney, B. W., Fullton, L. K., & Stetson, P. B. 2001, AJ, 122, 3136 [ Links ]
Lee, K. H., Lee, H. M., Fahlman, G. G., & Lee, M. G. 2003, AJ, 126, 815 [ Links ]
Luridiana, V., Peimbert, A., Peimbert, M., & Cervino, M. 2003, ApJ, 592, 846 [ Links ]
McNamara, D. H. 1997, PASP, 109, 857 [ Links ]
Pietrinferni, A., Cassisi, S., Salaris, M., & Castelli, F. 2004, ApJ, 612, 168 [ Links ]
Proffitt, C. R., & VandenBerg, D. A. 1991, ApJS, 77, 473 [ Links ]
Reid, I. N. 1999, ARA&A, 37, 191 [ Links ]
Ruelas-Mayorga, A. 1991, RevMexAA, 22, 27 [ Links ]
Sandage, A. 1970, ApJ, 162, 841 [ Links ]
----------. 1982, ApJ, 252, 574 [ Links ]
----------. 1983, AJ, 88, 1159 [ Links ]
Sandage, A., & Walker, M. F. 1966, ApJ, 143, 313 [ Links ]
Sarajedini, A. 1994, AJ, 107, 618 [ Links ]
Sarajedini, A., & Layden, A. 1997, AJ, 113, 264 [ Links ]
Skillen, I., Fernley, J. A., Stobie, R. S., & Jameson, R. F. 1993, MNRAS, 265, 301 [ Links ]
Smith, H. 1988, A&A, 198, 365 [ Links ]
Stetson, P., & Harris, W. 1988, AJ, 96, 909 [ Links ]
Stetson, P. 2005, http://cadcwww.hia.nrc.ca/cadcbin/wdb/astrocat/stetson/query/ [ Links ]
Tsujimoto, T., Miyamoto, M., & Yoshii, Y. 1998, ApJ, 492L, 79 [ Links ]
VandenBerg, D. A. 1992, ApJ, 391, 685 [ Links ]
VandenBerg, D. A., Stetson, P. B., & Bolte, M. 1996, ARA&A, 34, 461 [ Links ]
Wan, L., Mao, Y. Q., & Ji, D. S. 1980, Ann. Shanghai Obs., 2, 1 [ Links ]
Yang, J., Turner, M. S., Schramm, D. N., Steigman, G., & Olive, K. A. 1984, ApJ, 281, 493 [ Links ]