HIGH PRECISION INFRARED SPECTROSCOPY OF OH+

The molecular ion OH$^{+}$ is of significant importance to interstellar chemistry. OH$^{+}$ is a key intermediate in the formation of water, and the ratios of OH$^{+}$ to H$_{2}$O$^{+}$ and H$_{3}$O$^{+}$ have been used to calculate the cosmic ray ionization rates in diffuse molecular clouds.footnote{F. Wyrowski textit{et al., Astron. Astrophys.}, (2010),textbf{26},5.}footnote{E. Gonzﾇlez-Alfonso textit{et al., Astron. Astrophys.,} (2013), textbf{550}, A25.}footnote{N. Indriolo textit{et al., Astrophys. J.}, (2015), textbf{800}, 40.} To improve on previous spectroscopic work, the sensitive technique Noise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy (NICE-OHVMS) has been used to record rovibrational transitions of OH$^+$. Previously this approach has been used to investigate HCO$^{+}$, H$_{3}^{+}$, CH$_{5}^{+}$, and HeH$^{+}$.footnote{J.N. Hodges textit{et al., Chem. Phys.}, (2013), textbf{139}, 164201.}footnote{A.J. Perry textit{et al., J. Chem. Phys.}, (2014), textbf{141}, 101101.} Using an optical frequency comb for precise frequency calibration, the OH$^+$ line centers have been determined with $sim$MHz uncertainties. Here the most precise and accurate list of rovibrational transitions of OH$^{+}$ is presented. These values can then be used to empirically determine rotational transitions through combination difference analysis