Spectral Energy and Age Distributions for 51 Globular Cluster Candidates

• Autorzy: Ma J. , Zhou X. , Chen J. , Wu H. , Kong X. , Jiang Z. , Zhu J. , Xue S.
• Języki publikacji: EN

Abstrakty

EN

This paper is the fourth in a series presenting spectrophotometry of 51 globular cluster candidates, that were detected by Mochejska et al. in the nearby galaxy M33 using the data collected by the DIRECT project. The frames of M33 in this study were taken as a part of the BATC Multicolor Sky Survey. We obtained the spectral energy distributions of these candidates in 13 intermediate-band filters. By comparing the integrated photometric measurements with theoretical stellar population synthesis models of Bruzual and Charlot, we estimated their ages. The BC96 models provide the evolution in time of the spectrophotometric properties of simple stellar populations for a wide range of stellar metallicity. Our results show that half of the candidates are younger than 10⁸ years. We also find that globular clusters formed continuously in M33 from ≈4×10⁶ to 10¹⁰ years. Our results are in agreement with Chandar et al. who estimated ages for 35 globular clusters candidates from our list by comparing the photometric measurements to integrated colors from theoretical models by Bertelli et al. The Kolmogorov-Smirnov test shows that the maximum value of the absolute difference of estimated ages between Chandar et al. and us is 0.48, and the significance level probability is 100.00%.

Słowa kluczowe

EN

galaxies: individual: M33; galaxies: evolution; galaxies: clusters: general

• Wydawca: Copernicus Foundation for Polish Astronomy
• Czasopismo: Acta Astronomica
• Rocznik: 2002
• Tom: Vol. 52, No. 4
• Strony: 453--470
• Opis fizyczny: Bibliogr. 45 poz., tab., wykr., zdj.

Twórcy

autor

Ma J.

• National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012, P. R. China

autor

Zhou X.

• National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012, P. R. China

autor

Chen J.

• National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012, P. R. China

autor

Wu H.

• National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012, P. R. China

autor

Kong X.

• Center for Astrophysics, University of Science and Technology of China, Hefei, 230026, P. R. China

autor

Jiang Z.

• National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012, P. R. China

autor

Zhu J.

• National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012, P. R. China

autor

Xue S.

• National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012, P. R. China

Bibliografia

• Bertelli, G., Bressan, A., Chiosi, C., Fagotto, F., and Nasi, E. 1994, Astron. Astrophys. Suppl. Ser.,
• 106, 275. Bressan, A., Chiosi, C., and Tantalo, R. 1996, Astron. Astrophys., 311, 425.
• Bruzual, G., and Charlot, S. 1993, Astrophys. J., 405, 538.
• Buzzoni, A. 1997, in: IAU Symp. 183, "Cosmological Parameters and Evolution of the Universe", Ed. K. Sato (Dordrecht: Kluwer), p. 18.
• Chandar, R., Bianchi, L., and Ford, H.C. 1999a, Astrophys. J. Suppl. Ser., 122, 431.
• Chandar, R., Bianchi, L., and Ford, H.C. 1999b, Astrophys. J., 517, 668.
• Chandar, R., Bianchi, L., Ford, H.C., and Salasnich, B. 1999c, P.A.S.P., 111, 794.
• Chandar, R., Bianchi, L., and Ford, H.C. 2001, Astron. Astrophys., 366, 498.
• Charlot, S., and Bruzual, G. 1991, Astrophys. J., 367, 126.
• Chiosi, C., Bressan, A., Portinari, L., and Tantalo, R. 1998, Astron. Astrophys., 339, 355.
• Christian, C.A., and Schommer, R.A. 1982, Astrophys. J. Suppl. Ser., 49, 405.
• Christian, C.A., and Schommer, R.A. 1983, Astrophys. J., 275, 92.
• Christian, C.A., and Schommer, R.A. 1988, Astron. J., 95, 704.
• Fan, X., et al. 1996, Astron. J., 112, 628.
• Fioc, M., and Rocca-Volmerange, B. 1997, Astron. Astrophys., 326, 950.
• Freedman, W.L.,Wilson, C.D., and Madore, B.F. 1991, Astrophys. J., 372, 455.
• Galadí-Enríquez, D., Trullols, E., and Jordi, C. 2000, Astron. Astrophys. Suppl. Ser., 146, 169.
• Hiltner, W.A. 1960, Astrophys. J., 131, 163.
• Jablonka, P., Bica, E., Pelat, D., and Alloin, D. 1996, Astron. Astrophys., 307, 385.
• Kaluzny, J., Stanek, K.Z., Krockenberger, M., Sasselov, D., Tonry, J.L., and Mateo, M. 1998, Astron. J., 115, 1016.
• Kennicutt, R.C. 1998, Ann. Rev. Astron. Astrophys., 36, 189.
• Kong, X., et al. 2000, Astron. J., 119, 2745.
• Kron, G.E., and Mayall, N.U. 1960, Astron. J., 65, 581.
• Landolt, A.U. 1983, Astron. J., 88, 439.
• Landolt, A.U. 1992, Astron. J., 104, 340.
• Leitherer, C., et al. 1996, P.A.S.P., 108, 996.
• Leitherer, C., et al. 1999, Astrophys. J. Suppl. Ser., 123, 3.
• Ma, J., Zhou, X., Kong, X., Wu, H., Chen, J., Jiang, Z., Zhu, J., and Xue, S. 2001, Astron. J., 122, 1796.
• Ma, J., Zhou, X., Chen, J., Wu, H., Jiang, Z., Xue, S., and Zhu, J. 2002a, Astron. Astrophys., 385, 404.
• Ma, J., Zhou, X., Chen, J., Wu, H., Jiang, Z., Xue, S., and Zhu, J. 2002b, Astron. J., 123, 3141.
• Melnick, J., and D’Odorico, S. 1978, Astron. Astrophys. Suppl. Ser., 34, 249.
• Mochejska, B.J., Kaluzny, J., Krockenberger, M., Sasselov, D.D., and Stanek, K.Z. 1998, Acta Astron., 48, 455.
• Sarajedini, A.A., Geisler, D., Harding, P., and Schommer, R. 1998, Astrophys. J. Letters, 508, L37.
• Schaerer, D., and de Koter, A. 1997, Astron. Astrophys., 322, 598.
• Schaerer, D., and Vacca, W.D. 1998, Astrophys. J., 497, 618.
• Schmidt, A.A., Bica, E., and Alloin, D. 1990, MNRAS, 243, 620.
• Searle, L., Sargent, W.L.W., and Bagnuolo, W.G. 1973, Astrophys. J., 179, 427.
• Stanek, K.Z., Kaluzny, J., Krockenberger, M., Sasselov, D.D., Tonry, J.L., and Mateo, M. 1998, Astron. J., 115, 1894.
• Stetson, P.B. 1987, P.A.S.P., 99, 191.
• Tinsley, B.M. 1972, Astron. Astrophys., 20, 382.
• Yan, H.J., et al. 2002, P.A.S.P., 112, 691.
• Zheng, Z.Y., et al. 1999, Astron. J., 117, 2757.
• Zhou, X., Jiang, Z.-J., Xue, S.-J., Wu, H., Ma, J., and Chen, J.-S. 2001, Chinese Astron. Astrophys., 1, 372.
• Zhou, X., et al. 2002, Astron. Astrophys., in press.
• Zombeck, M.V. 1990, Handbook of Space Astronomy and Astrophysics (2nd. ed; Cambrigde: Cambrigde Univ. Press) p. 104.