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, K-s) toward the Galactic center from the observations of the region vertical bar l vertical bar less than or similar to 2 degrees 0 and 0 degrees 5 less than or similar to vertical bar b vertical bar less than or similar to 1.degrees 0 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 AK(s)/EH-Ks =1: 44 +/- 0: 01, AK(s)/E-J-K-s = 0: 494 +/- 0: 006, and A(H)/EJ-H = 1: 42 +/- 0: 02, which are significantly smaller than those obtained in previous studies. From these ratios, we estimate that AJ : AH : AKs = 1: 0.573 +/- 0: 009: 0: 331 +/- 0: 004 and EJ-H/EH-Ks = 1: 72 +/- 0: 04, and we find that the power law A(lambda) alpha lambda(-1: 99 +/- 0:02) is a good approximation over these wavelengths. Moreover, we find a small variation in A(Ks)/EH-Ks 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.