TY - JOUR
T1 - The organic volatile composition of Oort cloud comets
T2 - Evidence for chemical diversity in the giant-planets' nebular region
AU - Mumma, M. J.
AU - DiSanti, M. A.
AU - Dello Russo, N.
AU - Magee-Sauer, Karen
AU - Gibb, E.
AU - Novak, R.
PY - 2002/7/1
Y1 - 2002/7/1
N2 -
Organic volatiles and water in eight Oort cloud comets were investigated at infrared wavelengths. The detected species include H
2
O, CO, CH
3
OH, CH
4
, C
2
H
2
, C
2
H
6
, OCS, HCN, NH
3
, and H
2
CO. Several daughter fragments (CN, OH, NH
2
, etc.) are also measured. OH prompt emission provides a useful proxy for water. Long-slit spectra are taken at high spectral dispersion and high spatial resolution, eliminating several sources of systematic error. The resulting parent volatile production rates are highly robust, permitting a sensitive search for compositional diversity among comets. Here, seven OC comets are compared. Six (including Halley) exhibit similar compositions (excepting CO). Their low formation temperatures (∼ 30K) suggest this group probably formed beyond 30 AU from the young sun. However, C/1999 S4 is severely depleted in hypervolatiles and also in methanol, and it likely formed near 5 - 10 AU. C/2001 A2 is discussed briefly to illustrate future prospects.
AB -
Organic volatiles and water in eight Oort cloud comets were investigated at infrared wavelengths. The detected species include H
2
O, CO, CH
3
OH, CH
4
, C
2
H
2
, C
2
H
6
, OCS, HCN, NH
3
, and H
2
CO. Several daughter fragments (CN, OH, NH
2
, etc.) are also measured. OH prompt emission provides a useful proxy for water. Long-slit spectra are taken at high spectral dispersion and high spatial resolution, eliminating several sources of systematic error. The resulting parent volatile production rates are highly robust, permitting a sensitive search for compositional diversity among comets. Here, seven OC comets are compared. Six (including Halley) exhibit similar compositions (excepting CO). Their low formation temperatures (∼ 30K) suggest this group probably formed beyond 30 AU from the young sun. However, C/1999 S4 is severely depleted in hypervolatiles and also in methanol, and it likely formed near 5 - 10 AU. C/2001 A2 is discussed briefly to illustrate future prospects.
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M3 - Article
AN - SCOPUS:0036664791
SP - 753
EP - 762
JO - European Space Agency, (Special Publication) ESA SP
JF - European Space Agency, (Special Publication) ESA SP
SN - 0379-6566
IS - 500
ER -