Blake, Cullen H.Charbonneau, DavidWhite, Russel J.Marley, Mark S.Saumon, Didier2019-09-242007Blake, Cullen H., David Charbonneau, Russel J. White, Mark S. Marley, and Didier Saumon. 2007. “Multiepoch Radial Velocity Observations of L Dwarfs.” The Astrophysical Journal 666 (2): 1198–1204. https://doi.org/10.1086/520124.0004-637X1538-4357http://nrs.harvard.edu/urn-3:HUL.InstRepos:41397418We report on the development of a technique for precise radial velocity measurements of cool stars and brown dwarfs in the near infrared. Our technique is analogous to the iodine (I-2) absorption cell method that has proven so successful in the optical regime. We rely on telluric CH4 absorption features to serve as a wavelength reference, relative to which we measure Doppler shifts of the CO and H2O features in the spectra of our targets. We apply this technique to high-resolution (R approximate to 50; 000) spectra near 2.3 mu m of nine L dwarfs taken with the Phoenix instrument on Gemini South and demonstrate a typical precision of 300 m s(-1). We conduct simulations to estimate our expected precision and show that our performance is currently limited by the signal-to-noise ratio (S/N) of our data. We present estimates of the rotational velocities and systemic velocities of our targets. With our current data we are sensitive to companions with M sin i > 2 M-J in orbits with periods less than 3 days. We identify no companions in our current data set. Future observations with improved S/N should result in radial velocity precision of 100 m s(-1) for L dwarfs.en-USJournal Article2019-09-2410.1086/520124