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The kinematics and zero point of the log P - <MK> relation for galactic field RR Lyrae variables via statistical parallaxстатья
- Авторы: Dambis A.K., Vozyakova O.V.
- Сборник: ASP Conference Proceedings
- Том: 310
- Год издания: 2004
- Место издания: Astronomical Society of the Pacific San Francisco, United States
- Первая страница: 128
- Последняя страница: 131
- Аннотация: The kinematical parameters of the local field RR Lyrae population and the zero point of the log P - K> relation for these variables are inferred by applying the statistical parallax (maxium-likelihood) technique to a sample of 379 RR Lyrae stars with known periods, radial velocities, metallicities, K-band photometry, and absolute proper motions on the ICRS system. Hipparcos, Tocho-2, SPM, UCAC1 and NPM1 were used as the sources of proper motions. The K-band magnitudes were adopted from the 2MASS All-Sky Data Release. The parameters of the velocity distribution are found to be (U0 = -13 ± 9, V0 = -41 ± 7, W0 = -19±4) kms-1, (σU = 66±9, σV = 47±7, σW = 23±5) kms-1 and (U0 = -11±10, V0 = -224±8, W0 = -8±6) kms-1 (σU = 158±9, σV = 95±5, σW = 88±5) kms-1 for the thick-disk (the purest disk sample, 56 stars) and halo (the purest halo sample, 264 stars) objects, respectively. The zero point of the infared PL relation of Jones et al. (1992 - based on the results obtained using the Baade-Wesselink method) is confirmed: we find K> = -2.33·log PF -0.89±0.09, which is only 0.m01 brighter than found using the Baade-Wesselink method (Jones et al. 1992). A conversion of the resulting log P- K> relation to V-band luminosities yields the metallicity-luminosity relation V> = +1.12 + 0.18·[Fe/H] ± 0.10. Our results imply a solar Galactocentric distance of R0 = 7.8±0.4 kpc and an LMC distance modulus of DMLMC = 18.17±0.10 (cluster RR Lyraes) or DMLMC = 18.10±0.10 (field RR Lyraes), thereby favoring the so-called short distance scale.
- Добавил в систему: Дамбис Андрей Карлович