Mathematics – Probability
Scientific paper
Feb 1978
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1978apj...220..124d&link_type=abstract
Astrophysical Journal, Part 1, vol. 220, Feb. 15, 1978, p. 124-128. Research supported by the National Research Council of Cana
Mathematics
Probability
60
Astronomical Models, Atomic Recombination, Depletion, Interstellar Matter, Recombination Reactions, Aluminum, Boron, Calcium, Cations, Chemical Properties, Chromium, Copper, Elements, Grains, Ionic Collisions, Iron, Magnesium, Manganese, Silicon Dioxide, Titanium
Scientific paper
A model for the reaction of positive ions with negatively charged species on oxide grain surfaces is proposed which involves recombination of a gas-phase ion with surface O(-) or OH(-). The excess energy associated with this reaction is shown to generate surface transitions similar to those responsible for the 2175-A extinction feature. When this excess energy is close to 5.7 eV, the ion is retained by the grain surface. If the excess energy differs by more than (+ 1.0, -1.5) eV from 5.7 eV, the probability that the element is retained is small. This leads to selective depletion of Al, Ca, Cr, Ti, Mn, Mg, Ni, Cu, Fe, Si, and B. These selective effects are shown to arise when ions collide with small grains. Larger grains are responsible for a uniform depletion experienced by all elements. Overall depletions are the result of both mechanisms. Comparison of the depletion of a selectively depleted element such as Ca with that of an element such as Na that is not selectively depleted leads to an estimate of the radii of the two grain types.
Duley Walter W.
Millar Thomas J.
No associations
LandOfFree
Elemental depletions in the interstellar medium 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 Elemental depletions in the interstellar medium, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Elemental depletions in the interstellar medium will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1034336