Theoretical Isochrones with Extinction in the K Band. II. J - K versus K

Abstract

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.

Published in PASP, 118, 62 (Jan. 2006)

References in corpus (3)

• Theoretical isochrones in several photometric systems I. Johnson-Cousins-Glass, HST/WFPC2, HST/NICMOS, Washington, and ESO Imaging Survey filter sets
• An Extended Star Formation History for the Galactic Center from Hubble Space Telescope/NICMOS Observations
• Theoretical Isochrones with Extinction in the K Band

Cited by in corpus (4)

• The massive star initial mass function of the Arches cluster
• The Starburst Cluster Westerlund 1: The Initial Mass Function and Mass Segregation
• The Optical/Near-Infrared Extinction Law In Highly Reddened Regions
• Reddening Behaviors of Galaxies in the SDSS Photometric System