2Mass two-color interstellar reddening lines: the band-width effect

Abstract

The band-width effect on interstellar reddening lines in the J-H vs. H-Ks diagram of the 2MASS survey is investigated using synthetic color indices and color excesses based on the Kurucz model atmospheres. At large interstellar reddenings {EH-KS > 1-0) reddening lines deviate considerably from a straight line. The lines can be approximated by a parabolic equation: EJ-H = rEH-Ks + S^H-KS where the slope coefficient, r, and the curvature coefficient, 5, depend slightly on the intrinsic energy distribution of the source. The curvature of the reddening lines is confirmed by the J-H vs. H-Ks diagrams plotted by Straižys and Laugalys (2008) from 2MASS observations.