and a corresponding dark frame were obtained for flat-fielding.

Data Reduction Methods
----------------------

For the data reduction we used REDSPEC, an IDL-based software package developed at UCLA for NIRSPEC by S. Kim, L. Prato, and I. McLean[^3]. For each echelle order, REDSPEC uses the position of the two-dimensional spectra on the NIRSPEC array and the calibration line spectra to construct spatial and spectral maps necessary to transform the raw data onto a uniform grid. If the target spectrum itself is too faint to provide the spatial rectification, then the A0V star observed with the same set up was used instead. Although four arc lamps are available, it is often the case that there are too few well-distributed lines per echelle order for good spectral rectification. Consequently, OH night sky lines were also used. The dispersion was more than adequately fit by a second order polynomial of the form $\lambda = c_{0} + c_{1} x + c_{2} x^{2}$ where $c_{1} \sim$ 0.17$\pm$0.01 Å/pixel and $c_{2} \sim$ 7 x 10$^{-6}$  Å/pixel$^2$. To extract spectra free from atmospheric background and uneven detector response, the difference of an A/B image pair was formed and flat-fielded. The flat-fielded difference frame was then rectified using the 