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تسجيل مستخدم جديدInterstellar Extinction Law toward the Galactic Center II: V, J, H, and Ks Bands
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We have determined the ratios of total to selective extinction directly from observations in the optical V band and near-infrared J band toward the Galactic center. The OGLE (Optical Gravitational Lensing Experiment) Galactic bulge fields have been observed with the SIRIUS camera on the IRSF telescope, and we obtain A(V)/E(V-J)=1.251+-0.014 and A(J)/E(V-J)=0.225+-0.007. From these ratios, we have derived A(J)/A(V) = 0.188+-0.005; if we combine A(J)/A(V) with the near-infrared extinction ratios obtained by Nishiyama et al. for more reddened fields near the Galactic center, we get A(V) : A(J) : A(H) : A(Ks) = 1 : 0.188 : 0.108 : 0.062, which implies steeply declining extinction toward the longer wavelengths. In particular, it is striking that the Ks band extinction is approx 1/16 of the visual extinction A(V) much smaller than one tenth of A(V) so far employed.
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We have determined the wavelength dependence of the extinction in the near-infrared bands ($J$, $H$, $K_{mathrm S}$) toward the Galactic center from the VVV (VISTA Variables in the Via Lactea) aperture photometry of the stars in the region $|l|lesssi
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