| Theoretical isochrones with extinction in the K band. II. J - K versus K (2006) | |||||||||||||||
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| Published PASP Jan Theoretical Isochrones with Extinction the Band versus Sungsoo Kim Donald Figer and Myung Gyoon Lee arXiv astro Jan ABSTRACT calculate theoretical isochrones consistent way for five filter pairs near the and band atmospheric windows K W and M using the Padova stellar evolutionary models Girardi present magnitude transformations between various band filters function color Isochrones with extinction mag the band are also presented found for the filter pairs composed K band filters find that the reddened isochrones different filter pairs behave they follow different extinction laws and that the extinction curves Hubble Space Telescope NICMOS filter pairs the color magnitude diagram are considerably nonlinear Because these problems extinction values estimated with NICMOS filters can error mag Our calculation suggests that the extinction law implied the observations Rieke for wavelengths between the and bands better described power law function with exponent instead which commonly used with assumption that the transmission functions and filters are Dirac delta functions Subject headings Hertzsprung Russell diagram techniques photometric stars fundamental parameters infrared stars INTRODUCTION Kim hereafter Paper have calculated theoretical isochrones with extinction for some and band filters using the Padova stellar evolutionary models Girardi In Paper found that the reddened isochrones different filter pairs and bands behave they follow different extinction law. We calculate theoretical isochrones in a consistent way for five filter pairs near the J and K band atmospheric windows (J–K, J–K′, J–Ks, F110W–F205W, and F110W–F222M) using the Padova stellar evolutionary models of Girardi et al. We present magnitude transformations between various K-band filters as a function of color. Isochrones with extinction of up to 6 mag in the K band are also presented. As found for the filter pairs composed of H & K band filters, we find that the reddened isochrones of different filter pairs behave as if they follow different extinction laws, and that the extinction curves of Hubble Space Telescope NICMOS filter pairs in the color-magnitude diagram are considerably nonlinear. Because of these problems, extinction values estimated with NICMOS filters can be in error by up to 1.3 mag. Our calculation suggests that the extinction law implied by the observations of Rieke et al for wavelengths between the J and K bands is better described by a power-law function with an exponent of 1.66 instead of 1.59, which is commonly used with an assumption that the transmission functions of J and K filters are Dirac delta functions. (Refer to PDF file for exact formulas).. S. S. K. was supported by the Astrophysical Research Center for the Structure and Evolution of the Cosmos (ARCSEC) of the Korea Science and Engineering Foundation through the Science Research Center (SRC) program. M. G. L. was in part supported by the ABRL (R14-2002-058-01000-0) and the BK21 program. | |||||||||||||||
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