set up with the NIRSPEC-3 order-sorting filter and specific echelle and cross-dispersion grating angles to record 11 echelle orders ($m$ = 66 to $m$ = 56) covering the wavelength range from 1.15–1.36$\mu$m, corresponding approximately to the standard $J$-band. The free spectral range ($\lambda_{b}/m$) at 1.255 $\mu$m (order 61) is $\sim$206 Å, but the effective dispersion is 0.179 Å/pixel, allowing for only 183 Å  (89%) of this order to be captured by the detector. In fact, the captured wavelength range varies from 171 Å  (94%) in order 65 to 192  Å  (84%) in order 58. Thus, because the spectral interval captured by the detector is slightly smaller than the free spectral range in each order, there are small gaps, increasing with wavelength, in the total spectral coverage. Table 2 summarizes the spectral range for each order used in the subsequent analysis. In practice, for an entrance slit 0$\farcs$43 (3 pixels) wide, the final spectral resolution in the reduced data is $R \sim 20,000$, (or 15 km s$^{-1}$), compared to the theoretical value of $R = 24,000$. The average value of one spectral resolution element is $\sim$0.625Å  (equivalent to 3.6 pixels) over most of the $J$-band region.

Spectroscopic observations were made as 