Icarus 184 (2006) 255–276 www.elsevier.com/locate/icarus A high-resolution infrared spectral survey of Comet C/1999 H1 Lee Neil Dello Russo a,b,c,∗ , Michael J. Mumma b , Michael A. DiSanti d , Karen Magee-Sauer e , Erika L. Gibb f , Boncho P. Bonev b,g , I.S. McLean h , Li-Hong Xu i a Department of Physics, The Catholic University of America, Washington, DC 20064, USA b Solar System Exploration Division, NASA Goddard Space Flight Center, Code 690, Greenbelt,MD 20771, USA c The Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723-6099, USA d Planetary Systems Laboratory, Solar System Exploration Division, NASA Goddard Space Flight Center, Code 693, Greenbelt, MD 20771, USA e Department of Chemistry and Physics, Rowan University, Glassboro, NJ 08028, USA f Department of Physics and Astronomy, University of Missouri–St. Louis, St. Louis, MO 63121, USA g Ritter Astrophysical Research Center, Department of Physics and Astronomy, The University of Toledo, Toledo, OH 43606, USA h Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, CA 90095-1562, USA i Department of Physical Sciences, Centre for Laser, Atomic and Molecular Sciences, University of New Brunswick, Saint John, NB E2L 4L5, Canada Received 23 September 2005; revised 3 April 2006 Available online 3 July 2006 Abstract We obtained high-resolution (λ/λ ∼ 25,000) spectra of Comet C/1999 H1 (Lee) on UT 1999 August 19.6 and 21.6 using the cross-dispersed Near InfraRed SPECtrometer (NIRSPEC) at the Keck Observatory atop Mauna Kea, HI. Here we present spectra of Comet Lee between 2.874 and 3.701 μm (3479–2702 cm −1 ) representing the most complete high-resolution infrared survey of a comet to date in this wavelength region. Using published line lists and laboratory spectra we have identified 444 of the 545 distinct emission features present in these spectra. We have tabulated the rest frequencies, assignments, relative intensities, and signal-to-noise ratios of all detected emissions. In addition to gaining insights into the chemistry of Comet Lee, this survey provides a valuable tool for planning future high-resolution infrared observations of comets and other astronomical targets, and for retrospective comparison to existing high-resolution infrared datasets.  2006 Elsevier Inc. All rights reserved. Keywords: Comets; Infrared; Observations; Spectroscopy 1. Introduction Comets are volatile-rich, relatively unaltered remnants from the birth of the Solar System, so knowledge of their compo- sition and structure gives information on the formation and evolution of volatile material within our Planetary System. The volatile compositions of comet nuclei have generally been in- ferred from the spectral signatures of gases forming their co- mae. While molecular dissociation fragments have been stud- ied for nearly one hundred years (cf. Swings et al., 1941), the determination of their native precursors is often difficult. For example, despite the presence of strong CN and C 2 emis- sions in cometary spectra, the identity and source (from ice * Corresponding author. Fax: +1 (240) 228 8939. E-mail address: neil.dello.russo@jhuapl.edu (N. Dello Russo). or dust) of their native precursors is still uncertain and in fact may differ among comets (cf. Manfroid et al., 2005; Combi and Fink, 1997). The ability to study molecules directly released from the comet nucleus (parent or native volatiles) was first demon- strated with the detection of CO in Comets West 1976 VI and Bradfield 1979 X (Feldman, 1983), although CO can also be produced in significant amounts as a dissociation fragment. Later, parent volatiles HCN (Despois et al., 1986; Schloerb et al., 1986) and H 2 O(Mumma et al., 1986) were detected in Comet Halley. Close spacecraft encounters with Comet Hal- ley also provided insights into the volatile content of the coma and the nucleus. Abundances of several parent volatiles were determined from data obtained from the neutral gas mass spectrometer (NMS) aboard Giotto (Eberhardt et al., 1987a; Eberhardt, 1999). A low spectral resolution infrared spectrom- 0019-1035/$ – see front matter  2006 Elsevier Inc. All rights reserved. doi:10.1016/j.icarus.2006.04.020