Astronomy and Astrophysics – Astrophysics
Scientific paper
Mar 1997
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997aipc..402..523t&link_type=abstract
Astrophysical implications of the laboratory study of presolar materials. AIP Conference Proceedings, Volume 402, pp. 523-544 (
Astronomy and Astrophysics
Astrophysics
15
Atomic, Molecular, And Chemical, And Grain Processes
Scientific paper
The high deuterium fractionation observed in many solar system bodies is generally taken as an indication of incorporation of interstellar material which never fully equilibrated with the solar nebula. In this paper, I review chemical processes that affect the deuteration of interstellar molecules. The emphasis is on identifying the major interstellar D-reservoirs available to the solar system in formation. Ion-molecule reactions driven by cosmic ray ionization are very efficient in deuterating interstellar molecules. However, the absolute levels of deuterated molecules produced this way are rather small and probably not very important to the solar nebula. An exception should be made for PAHs which may well lock up ~=1% of the D in dense cloud cores. The main effect of ion-molecule chemistry is to shift the atomic to molecular balance of deuterium (D/HD) in the direction of atomic D. As a result, the atomic D/H ratio in the gas phase is ~=1. Upon accretion on a grain surface, atomic D will deuterate grain mantle molecules such as H2O, CH3OH, H2CO, NH3, and CH4. This is likely the main route by which D was delivered to the outer, colder, solar system bodies. The chemistry of dense (~=106-108 cm-3), warm (100-200 K) Hot Cores in star forming regions is reviewed with the emphasis on deuterated molecules. The central role of methanol, outgassed from icy grain mantles, in driving molecular complexity in the gas phase is recognized. It is likely, that the material which ended up in the solar nebula, went through a similar Hot Core phase. Finally, interstellar chemistry may also have left its traces in the C, N, and O isotopes of organic material available to the Solar System.
No associations
LandOfFree
Deuterium and interstellar chemical processes 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 Deuterium and interstellar chemical processes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Deuterium and interstellar chemical processes will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1858448