Trapping of N2, CO and Ar in amorphous ice—Application to comets

Details Trapping of N2, CO and Ar in amorphous ice—Application to comets Trapping of N2, CO and Ar in amorphous ice—Application to comets

Oct 2007

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007icar..190..655b&link_type=abstract

Icarus, Volume 190, Issue 2, p. 655-659.

Astronomy and Astrophysics

Astrophysics

13

Scientific paper

Recent attempts using high resolution spectra to detect N+2 in several comets were unsuccessful [Cochran, A.L., Cochran, W.D., Baker, E.S., 2000. Icarus 146, 583 593; Cochran, A.L., 2002. Astrophys. J. 576, L165 L168]. The upper limits on N+2 in comparison with the positively detected CO+ for Comets C/1995 O1 Hale Bopp, 122P/1995 S1 de Vico and 153P/2002 C1 Ikeya Zhang range between N2+/CO<(0.65 5.4)×10. Ar was not detected in three recent comets [Weaver, H.A., Feldman, P.D., Combi, M.R., Krasnopolsky, V., Lisse, C.M., Shemansky, D.E., 2002. Astrophys. J. 576, L95 L98], with upper limits of Ar/CO<(3.4 7.8)×10 for Comets C/1999 T1 McNaught Hartley, C/2001 A2 LINEAR and C/2000 WM1 LINEAR. The Ar detected by Stern et al. [Stern, S.A., Slater, D.C., Festou, M.C., Parker, J.Wm., Gladstone, G.R., A'Hearn, M.F., Wilkinson, E., 2000. Astrophys. J. 544, L169 L172] for Comet C/1995 O1 Hale Bopp, gives a ratio Ar/CO=7.25×10, which was not confirmed by Cosmovici et al. [Cosmovici, C.B., Bratina, V., Schwarz, G., Tozzi, G., Mumma, M.J., Stalio, R., 2006. Astrophys. Space Sci. 301, 135 143]. Trying to solve the two problems, we studied experimentally the trapping of N+CO+Ar in amorphous water ice, at 24 30 K. CO was found to be trapped in the ice 20 70 times more efficiently than N2 and with the same efficiency as Ar. The resulting Ar/CO ratio of 1.2×10 is consistent with Weaver et al.'s [Weaver, H.A., Feldman, P.D., Combi, M.R., Krasnopolsky, V., Lisse, C.M., Shemansky, D.E., 2002. Astrophys. J. 576, L95 L98] non-detection of Ar. However, with an extreme starting value for N2/CO = 0.22 in the region where the ice grains which agglomerated to produce comet nuclei were formed, the expected N2/CO ratio in the cometary ice should be 6.6×10, much higher than its non-detection limit.

Affiliated with

Also associated with

No associations

Rating

Trapping of N2, CO and Ar in amorphous ice—Application to comets does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Trapping of N2, CO and Ar in amorphous ice—Application to comets, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Trapping of N2, CO and Ar in amorphous ice—Application to comets will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1866781