deletions | additions       diff --git a/Observations spectra.tex b/Observations spectra.tex  index d7ccb08..dfabc22 100644  --- a/Observations spectra.tex  +++ b/Observations spectra.tex 
...
% ^^ the above isn't relevant anymore now that we have section wavelength, below.  \subsubsection{APOGEE spectra from APO}\label{apogee}  We finally obtained two near-IR spectra of KIC 9246715 from the Sloan Digital Sky Survey-III (SDSS-III) Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey \citep{2015arXiv150100963A}. The wavelength range for APOGEE is 1.5--1.7 microns $\mu$m  with a nominal resolution of 22,500. The pair of spectra were reduced with the standard APOGEE pipeline, but not combined. \subsubsection{Global wavelength solution}\label{wavelength}  Because the observations come from three different spectroscopes at two different observatory sites, it is critical to apply a consistent wavelength solution that yields the same radial velocity zeropoint for all observations. This zeropoint is a function of the air at the observatory site and the instrument being used. Typically such a correction can be done with RV standard stars after a wavelength solution has been applied based on ThAr lamp observations. However, we lacked RV standard star observations, and some of the earlier ARCES observations had insufficiently frequent ThAr calibration images to arrive at a reliable wavelength solution. (We subsequently took ThAr images more frequently to address the latter issue.) To arrive at a consistent velocity zeropoint for all spectra, we used TelFit \citep{gul14} to fit generate  a telluric line model of the O2 A-band (7595--7638 \AA) with $R = 31,000$  at STP to STP. We then shifted  the ARCES and TRES observations. We shifted each spectrum spectra  in velocity space using the Broadening Function technique (see Section \ref{rvs}) so they all line up with the TelFit model. The shifts ranged from $-0.88 - 2.18$ km s$^{-1}$, with the majority having a magnitude $< 0.3$ km s$^{-1}$. %APOGEE spectra are fiber-fed and reported in vacuum wavelengths, TRES spectra are fiber-fed and typically calibrated to CfA-standard air wavelengths, and ARCES spectra are slit-based and typically reported in local air wavelengths.