\times 12$ & 100\
2012-07-28 10:40&2456136.94978&[GCC-d]{}&$H$&$300 \times  8$ & 85

Analysis
========

Data reduction of the spectra was performed by standard procedures, including background subtraction, wavelength calibration, and normalization using the Image Reduction and Analysis Facility (IRAF[^1]). Wavelength calibration was based on the telluric absorption lines within individual target spectra. Spectra of each object in each run were combined into a single spectrum and normalized by the continuum level which can be reasonably traced. We retained the telluric absorption lines for redshift measurements, as explained below. Detailed plots of the target Cepheid spectra are compared in Figure \[fig:comp2\]. Clear differences are observed in the redshifts of the four objects.

![ Detailed plot of the Subaru/IRCS spectra in the $H$-band for four Cepheids (data collected in July 2012). Vertical dotted lines indicate telluric lines used for wavelength calibration. Intrinsic absorption lines show different redshifts of the targets. \[fig:comp2\]](fig2.ps){width="0.98\hsize"}

To estimate the radial velocities, we compared the observed spectra with synthetic spectra constructed by the tools ATLAS9 and SYNTHE developed by @Kurucz-1993[^2]. They calculate plane-parallel atmospheric models and generate the synthetic spectra for a given stellar parameter set including the effective temperature $T_{\rm eff}$ and the gravity $\log g$. These tools do 