Photometric Study of the Star Cluster NGC 2155 in the Large Magellanic Cloud: Age Estimation and Variable Stars

• Autorzy: Otulakowska M. , Olech A. , Pych W. , Pamyatnykh A. A. , Zdravkov T. , Rucinski S. M.
• Języki publikacji: EN

Abstrakty

EN

We present results of new photometry for the globular star cluster NGC 2155 in the Large Magellanic Cloud (LMC). Our I- and V-band observations were obtained with the 6.5-m Magellan-1 Baade Telescope at Las Campanas Observatory resulting in deep photometry down to V≈24 mag. By analyzing the color-magnitude diagram for the cluster and utilizing the Victoria-Regina grid of isochrones models we estimated the age of the cluster at ≅2.25 Gyr and [Fe/H]=-0.71, the numbers which place NGC 2155 outside the age-gap in the age-metallicity relation for LMC clusters. Using the Difference Image Analysis Package (DIAPL), we detected 7 variable stars in the cluster field with variability at the level of 0.01 mag in the I-band. Three variable stars are particularly interesting: two SX Phe stars pulsating in the fundamental mode, and a detached eclipsing binary which is a prime candidate to estimate the distance to the cluster.

Słowa kluczowe

EN

Magellanic Clouds; galaxies: star clusters individual: NGC 2155; stars: variables: general

• Wydawca: Copernicus Foundation for Polish Astronomy
• Czasopismo: Acta Astronomica
• Rocznik: 2011
• Tom: Vol. 61, No. 2
• Strony: 161--177
• Opis fizyczny: Bibliogr. 43 poz., rys., tab., wykr.

Twórcy

autor

Otulakowska M.

• N. Copernicus Astronomical Center, Polish Academy of Sciences, ul. Bartycka 18, 00-716 Warsaw, Poland

autor

Olech A.

• N. Copernicus Astronomical Center, Polish Academy of Sciences, ul. Bartycka 18, 00-716 Warsaw, Poland

autor

Pych W.

• N. Copernicus Astronomical Center, Polish Academy of Sciences, ul. Bartycka 18, 00-716 Warsaw, Poland

autor

Pamyatnykh A. A.

• N. Copernicus Astronomical Center, Polish Academy of Sciences, ul. Bartycka 18, 00-716 Warsaw, Poland
• Institute of Astronomy, Russian Academy of Sciences, Pyatnitskaya Str. 48, 109017Moscow, Russia

autor

Zdravkov T.

• N. Copernicus Astronomical Center, Polish Academy of Sciences, ul. Bartycka 18, 00-716 Warsaw, Poland

autor

Rucinski S. M.

• Department of Astronomy and Astrophysics, University of Toronto, Toronto, ONM5S 3H4, Canada

Bibliografia

• Alard, C. 2000, A&AS, 144, 363.
• Alard, C., and Lupton, R.H. 1998, ApJ, 503, 325.
• Balbinot, E., Santiago, B.X., Kerber, L.O., Barbuy, B., and Dias, B.M.S. 2010, MNRAS, 404, 1625.
• Baume, G., Carraro, G. Costa, E., Méndez, R.A., and Girardi, L. 2007, MNRAS, 375, 1077.
• Beasley, M.A., Hoyle, F., and Sharples, R.M. 2002, MNRAS, 336, 168.
• Benedict, G.F., et al. 2002, AJ, 124, 1695.
• Bertelli, G., Nasi, E., Girardi, L., Chiosi, C., Zoccali, M., and Gallart, C. 2003, AJ, 125, 770.
• Bessell, M.S., Castelli, F., and Plez, B. 1998, A&A, 333, 231.
• Cole, A.A., Grocholski, A.J., Geisler, D., Sarajedini, A., Smith, V.V., and Tolstoy, E. 2009, in: “The Magellanic System: Stars, Gas, and Galaxies”, IAU Symposium, 256, 263.
• Dziembowski, W.A. 1977, Acta Astron., 27, 95.
• Dziembowski, W.A., and Pamyatnykh, A.A. 2008, MNRAS, 385, 2061.
• Fedorova, A.V., Tutukov, A.V., and Yungelson, L.R. 2004, Astronomy Letters, 30, 73.
• Fernie, J.D. 1992, AJ, 103, 1647.
• Gallart, C., Zoccali, M., Bertelli, G., Chiosi, C., Demarque, P., Girardi, L., Nasi, E., Woo, J-H., and Yi, S. 2003, AJ, 125, 742.
• Geisler, D., Bica, E., Dottori, H., Claria, J.J., Piatti, A.E., and Santos, J.F.C. 1997, AJ, 114, 1920.
• Gilliland, R.L., Bono, G., Edmonds, P.D., Caputo, F., Cassisi, S., Petro, L.D., Saha, A., and Shara, M.M. 1998, ApJ, 507, 818.
• Grevesse, N., and Noels, A. 1993, in: “Origin and evolution of the elements”, Symposium, 15.
• Hog, E., and Petersen, J.O. 1997, A&A, 323, 827.
• Iglesias, C.A., and Rogers, F.J. 1996, ApJ, 464, 943.
• Jensen, J., Mould, J., and Reid, N. 1988, ApJS, 67, 77.
• Kerber, L.O., Santiago, B.X., and Brocato, E. 2007, A&A, 462, 139.
• Lombardi, J.C., and Rasio, F.A. 2002, in: “Stellar Collisions, Mergers and their Consequences”, ASP Conference Proceedings, 263, Ed. Michael M. Shara, 35.
• McNamara, D. 1997, PASP, 109, 1221.
• Nemec, J.M., Nemec, A.F.L., and Lutz, T.E. 1994, AJ, 108, 222.
• Olszewski, E.W., Schommer, R.A., Suntzeff, N.B., and Harris, H.C. 1991, AJ, 101, 515.
• Piatti, A.E., Sarajedini, A., Geisler, D., Bica, E., and Clariá, J.J. 2002, MNRAS, 329, 556.
• Poretti, E., et al. 2008, ApJ, 685, 947.
• Pych, W., Kaluzny, J., Krzeminski, W., Schwarzenberg-Czerny, A., and Thompson, I.B. 2001, A&A, 367, 148.
• Rich, R.M., Shara, M.M., and Zurek, D. 2001, AJ, 122, 842.
• Rodríguez, E., and López-González, M.J. 2000, A&A, 359, 597.
• Rosenberg, A., Piotto, G., Saviane, I., and Aparicio, A. 2000, A&AS, 144, 5.
• Santolamazza, P., Marconi, M., Bono, G., Caputo, F., Cassisi, S., and Gilliland, R.L. 2001, ApJ, 554, 1124.
• Sarajedini, A. 1998, arXiv:astro-ph/9804340.
• Schlegel, D.J., Finkbeiner, D.P., and Davis, M. 1998, ApJ, 500, 525.
• Schwarzenberg-Czerny, A. 1996, ApJ, 460L, 107.
• Stetson, P.B. 1987, PASP, 99, 191.
• Thompson, I.B., Kaluzny, J., Rucinski, S.M., Krzeminski, W., Pych, W., Dotter, A., and Burley, G.S. 2010, AJ, 139, 329.
• Udalski, A. 1998, Acta Astron., 48, 383.
• VandenBerg, D.A. 2000, ApJS, 129, 315.
• VandenBerg, D.A., Bergbusch, P.A., and Dowler, P.D. 2006, ApJS, 162, 375.
• Woo, J.-H., Gallart, C., Demarque, P., Yi, S., and Zoccali, M. 2003, AJ, 125, 754.
• Wozniak, P.R. 2000, Acta Astron., 50, 421.
• Zaritsky, D., Harris, J., Thompson, I.B., and Grebel, E.K. 2004, AJ, 128, 1606.