Metallicity effects on the Cepheid distance scale
نویسندگان
چکیده
منابع مشابه
Theoretical models for classical Cepheids VII. Metallicity effects on the Cepheid distance scale
We use theoretical Period-Luminosity and Period-Luminosity-Color relations in the V I passbands, as based on nonlinear, nonlocal and time-dependent convective pulsating models, to predict the reddening and true distance modulus of distant Cepheids observed with the Hubble Space Telescope. By relying on the pulsating models with metal content Z=0.008, we find that the theoretical predictions agr...
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If a Cepheid luminosity at given period depends on metallicity, then the P-L relation in galaxies with higher metallicities may show a higher dispersion if these galaxies also sample a wider range of intrinsic metallicities. Using published HST Cepheid data from 25 galaxies, we have found such a correlation between the the P-L dispersion and host galaxy metallicity which is significant at the ≈...
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With the aid of stellar atmosphere models, we derive iron abundances [Fe/H] from the OGLE B, V , I photometry on the Magellanic Cloud Cepheids. We show that in both clouds the average metallicities of the first overtone variables are lower than those of the fundamental ones (by ∼ 0.2 and ∼ 0.3 dex in the LMC and SMC, respectively). Consequently, there is a correlation between the overall [Fe/H]...
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Hipparcos parallaxes have recently become available for a sample of Galactic Cepheids, and we have used these new distances to calibrate the Cepheid periodluminosity (PL) relation at six wavelengths (BV IJHK). Comparing these calibrations with previously published multiwavelength PL relations we find agreement to within 0.07 ± 0.14 mag, or 4 ±7% in distance. Unfortunately, the current parallax ...
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This study combines data from a set of seven Cepheid-calibrated galaxies in Virgo, Leo I and Fornax and four supernovæ with known metallicities, including metallicity corrections to the Cepheid distances, in order to determine a consistent mean value for the Hubble constant. We derive Virgo and Coma distances over different paths, starting from the metallicity corrected Cepheid distances of Vir...
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ژورنال
عنوان ژورنال: Symposium - International Astronomical Union
سال: 1991
ISSN: 0074-1809
DOI: 10.1017/s0074180900201186