Infrared Spectroscopy of the 3.0 tex2html_wrap_inline21 m Region: Observations with CSHELL of C/1995 O1 Hale-Bopp

K. Magee-Sauer (Rowan Univ.), M. J. Mumma, M. A. DiSanti, N. Dello Russo (GSFC), T. W. Rettig (Univ. of Notre Dame), R. Novak (Iona College)

We present results of spectroscopic observations of C/1995 O1 Hale-Bopp on UT dates: February 23/24, April 5/6, 7/8, 8/9, 29/30, and Apr 30/May 1 1997. The data were obtained using the CSHELL instrument at the NASA Infrared Telescope Facility on Mauna Kea, Hawaii. Spectra were obtained with the slit (1" by 30") centered on the nucleus. We targeted the P- and R- branches of HCN and C tex2html_wrap_inline23 H tex2html_wrap_inline23 and the Q-branch of NH tex2html_wrap_inline27 in the infrared region near 3.0 tex2html_wrap_inline21 m. The spectral resolution of CSHELL ( tex2html_wrap_inline31 ) was approximately 2 x 10^4. Detections of numerous ro-vibrational spectral lines of HCN (P2, P3, P4, P7, P8, R2, R6, R7) and a limited number of C_2H_2 lines (R1, R3, P3, P7) were achieved. NH_3 was marginally detected.

Molecular production rates of HCN, C_2H_2, and NH_3, and rotational temperatures for HCN will be presented. Unidentified species common to both Hale-Bopp and Hyakutake will be noted.

This work was supported by the NASA JOVE program, National Science Foundation RUI grant AST-9619461, Rowan University, and the NASA Planetary Astronomy Program under RTOP 344-32-03.