2000/03/08 by Anita L. Cochran, William D. Cochran, Edwin S. Barker · 1 citation
Physics and Astronomy · #astro-ph
paper · pdf · doi:10.1006/icar.2000.6413
25 pages, 3 tables, 7 figures, accepted for publication in Icarus
arxiv created 2000/03/08 · arxiv updated 2009/12/01
We observed comets 122P/1995 S1 (deVico) and C/1995 O1 (Hale-Bopp) with high spectral resolving power in order to determine the ratio of N2+/CO+ in their comae. While we clearly detected the CO+ in both of these comets, no N2+ was detected in either comet. From these spectra, we derive sensitive upper limits for N2+/CO+. These upper limits are substantially below other reported detections of N2+/CO+ in other comets. We discuss the prior N2+ detections and compare them with our observations. The abundance of N2 in comets is important to our understanding of the condensation of ices in the solar nebula. In addition, N2 is a tracer of Ar so study of N2 allows an understanding of the role of comets for delivering volatiles to the terrestrial planets. It appears that many, if not most, comets are depleted in N2 and it will be necessary to search for a mechanism for depleting this molecule in order to be consistent with current models of the solar nebula.