The Optical Gravitational Lensing Experiment. Cepheids in the Magellanic Clouds. III. Period-Luminosity-Color and Period-Luminosity Relations of Classical Cepheids

• Autorzy: Udalski A. , Szymański M. , Kubiak M. , Pietrzyński G. , Soszyński I. , Woźniak P. , Żebruń K.
• Języki publikacji: EN

Abstrakty

EN

We present Period-Luminosity-Color and Period-Luminosity relations of classical Cepheids constructed for about 1280 Cepheids from the LMC and 2140 from the SMC. High quality BVI observations (120-360 epochs in the I-band and 15-40 in the BV-bands) were collected during the OGLE-II microlensing experiment. The I-band diagrams of the LMC show very small scatter, σ=0.074 mag, indicating that Cepheid variables can potentially be a very good standard candle. We compare relations of fundamental mode Cepheids from the LMC and SMC and we do not find significant differences of slopes of the Period-Luminosity-Color and Period-Luminosity relations in these galaxies. For the first overtone Cepheids a small change of the slope of Period-Luminosity relation is possible. We determine the difference of distance moduli between the SMC and LMC with Cepheid relations and compare the result with the difference obtained with other standard candles: RR Lyr and red clump stars. Results are very consistent and indicate that the values of zero points of the fundamental mode Cepheid relations are similar in these galaxies. The mean difference of distance moduli between the SMC and LMC is equal to μ_SMC-μ_LMC=0.51±0.03 mag. We calibrate the Period-Luminosity-Color and Period-Luminosity relations for classical, fundamental mode Cepheids using the observed LMC relations and adopting the short LMC distance modulus, μ_LMC=18.22±0.05 mag, resulting from the recent determinations with eclipsing system HV2274, RR Lyr and red clump stars and consistent with observations of Cepheids in NGC 4258 galaxy, to which precise geometric distance is known. Finally, we determine a constraint on the absolute magnitude of Cepheids by comparison of their mean V-band magnitude with that of RR Lyr stars in both Magellanic Clouds. The 10-day period, fundamental mode Cepheid is on average 4.63±0.05 mag brighter than RR Lyr stars of LMC metallicity which with the most likely calibration of the brightness of RR Lyr stars yields MV^C,10=-3.92±0.09 mag.

Słowa kluczowe

EN

Cepheids; Magellanic Clouds; galaxies: distances and redshifts; distance scale

• Wydawca: Copernicus Foundation for Polish Astronomy
• Czasopismo: Acta Astronomica
• Rocznik: 1999
• Tom: Vol. 49, No. 3
• Strony: 201--211
• Opis fizyczny: Bibliogr. 38 poz., tab., wykr.

Twórcy

autor

Udalski A.

• Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland

autor

Szymański M.

• Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland

autor

Kubiak M.

• Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland

autor

Pietrzyński G.

• Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland

autor

Soszyński I.

• Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland

autor

Woźniak P.

• Princeton University Observatory, Princeton, NJ 08544-1001, USA

autor

Żebruń K.

• Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland

Bibliografia

• Alcock, C. et al. 1995, Astron. J., 109, 1652.
• Alibert, Y., Baraffe, I., Hauschildt, B., and Allard, F. 1999, Astron. Astrophys., 344, 551.
• Bauer, F. et al. 1999, Astron. Astrophys., 348, 175.
• Bica, E., Geisler, D., Dottori, H., Clari´a, J.J., Piatti, A.E., and Santos Jr, J.F.C. 1998, Astron. J., 116, 723.
• Bono, G., Caputo, F., Castellani, V., and Marconi, M. 1999, Astrophys. J., 512, 711.
• Caldwell, J.A.R., and Coulson, I.M. 1986, MNRAS, 218, 223.
• Chiosi, C., Wood, P.R., and Capitanio, N. 1993, Astrophys. J. Suppl. Ser., 86, 541.
• Feast, M.W., and Catchpole, R.M. 1997, MNRAS, 286, L1.
• Gould, A., and Uza, O. 1998, Astrophys. J., 494, 118.
• Gieren, W.P., Fouqu´e, P., and G´omez, M. 1998, Astrophys. J., 496, 17.
• Guinan, E.F. et al. 1998, Astrophys. J. Letters, 509, L21.
• Herrnstein, J.R. et al. 1999, Nature, 400, 539.
• Kennicutt, R.C., Freedman, W.L., and Mould,J.R. 1995, Astron. J., 110, 1476.
• Kennicutt, R.C., et al. 1998, Astrophys. J., 498, 181.
• Kochanek, C.S. 1997, Astrophys. J., 491, 13.
• Laney, C.D, and Stobie, R.S. 1994, MNRAS, 266, 441.
• Lanoix, P., Paturel, G., and Garnier, R. 1999, MNRAS, in press, (astro-ph/9904298).
• Leavitt, H.S. 1912, Harvard Cir., 173.
• Luck, R.E, Moffett, T.J., Barnes, T.G., and Gieren, W.P. 1998, Astron. J., 115, 605.
• Luri, X., Gómez, A.E., Torra, J., Figueras, F., and Mennessier, M.O. 1998, Astron. Astrophys., 335, 81.
• Maoz, E., et al. 1999, Nature, in press, (astro-ph/9908140).
• Madore, B.F., and Freedman, W.L. 1991, P.A.S.P., 103, 933.
• Panagia, N. 1998, Mem. Soc. Astron. Italiana, 69, 225.
• Popowski, P., and Gould, A. 1998, in "Post-Hipparcos Cosmic Candles, Eds. A.Heck and F.Caputo, Kluwer Academic Publ. Dordrecht; p. 53, astro-ph/9808006.
• Sasselov, D., et al. 1997, Astron. Astrophys., 324, 471.
• Schlegel, D.J., Finkbeiner, D.P., and Davis, M. 1998, Astrophys. J., 500, 525.
• Saio, H., and Gautchy, A. 1998, Astrophys. J., 498, 360.
• Stanek, K.Z. 1996, Astrophys. J. Letters, 460, L37.
• Stanek, K.Z, Zaritsky, D., and Harris, J. 1998, Astrophys. J. Letters, 500, L141.
• Udalski, A., Kubiak, M., and Szymański, M. 1997, Acta Astron., 47, 319.
• Udalski, A. 1998a, Acta Astron., 48, 113.
• Udalski, A. 1998b, Acta Astron., 48, 383.
• Udalski, A., Szymański, M., Kubiak, M., Pietrzyński, G., Woźniak, P., and Żerbuń, K. 1998a, Acta Astron., 48, 1.
• Udalski, A., Szymański, M., Kubiak, M.,Pietrzyński, G., Woźniak, P., and Żerbuń, K. 1998b, Acta Astron., 48, 147.
• Udalski, A., Pietrzyński, G., Woźniak, P., Szymański, M., Kubiak, M., and Żerbuń, K. 1998c, Astrophys. J. Letters, 509, L25.
• Udalski, A., Soszyński, I., Szymański, M., Kubiak, M., Pietrzyński, G., Woźniak, P., and Żerbuń, K. 1999a, Acta Astron., 49, 1.
• Udalski, A., Soszyński, I., Szymański, M., Kubiak, M., Pietrzyński, G., Woźniak, P., and Żerbuń, K. 1999b, Acta Astron., 49, 45.
• Walker, A.R. 1992, Astrophys. J. Letters, 390, L81