Interstellar Extinction Law in the J, H, and Ks Bands toward the Galactic Center

We have determined the ratios of total to selective extinction in the near-infrared bands (J,H,Ks) toward the Galactic center from the observations of the region [?] l [?] [?] 2.deg0 and 0.deg5 [?] [?] b [?] [?] 1.deg0 with the IRSF telescope and the SIRIUS camera. Using the positions of red clump stars in color-magnitude diagrams as a tracer of the extinction and reddening, we determine the average of the ratios of total to selective extinction to be Aimg1.gif/Eimg2.gif = 1.44 +- 0.01, Aimg1.gif/Eimg3.gif = 0.494 +- 0.006, and AH/EJ-H = 1.42 +- 0.02, which are significantly smaller than those obtained in previous studies. From these ratios, we estimate that AJ : AH : Aimg1.gif = 1 : 0.573 +- 0.009 : 0.331 +- 0.004 and EJ-H/Eimg2.gif = 1.72 +- 0.04, and we find that the power law Al [?] l-1.99+-0.02 is a good approximation over these wavelengths. Moreover, we find a small variation in Aimg1.gif/Eimg2.gif across our survey. This suggests that the infrared extinction law changes from one line of sight to another, and the so-called universality does not necessarily hold in the infrared wavelengths.