Phosphorus in circumstellar envelopes

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

11

Molecular Processes, Circumstellar Matter, Stars: Individual: Irc+10°216, Stars: Late-Type

Scientific paper

We have investigated the chemistry of phosphorus-bearing compounds in the circumstellar envelopes of both oxygen-rich and carbon-rich evolved stars. In accordance with thermodynamic calculations of photospheric chemistry, we have assumed that the dominant forms of phosphorus in the inner circumstellar envelope (CSE) are PS and HCP in each case. In the C-rich case, we can reproduce the observed CP abundance reasonably well if it is the photodaughter of HCP. In the O-rich case we find, for the same amount of P available in PS, that large abundances of atomic P are available for reaction but that a low abundance of PO can be produced. We have not extensively explored the effect of additional neutral processes since our results are partly compromised by the fact that neither HCP nor PS is detected in the three CSEs where searches have been made; our models predict column densities in excess of the published upper limits. Sensitive searches for these molecules at higher frequencies are required before their presence in circumstellar envelopes can definitely be ruled out. Dust condensation may incorporate all the available P into refractory grains and so we suggest that searches for P-bearing molecules may have the greatest opportunity for success in more evolved objects, such as protoplanetary nebulae, where P has been released from grains through the action of strong shock waves.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Phosphorus in circumstellar envelopes 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 Phosphorus in circumstellar envelopes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Phosphorus in circumstellar envelopes will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-802235

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.