The ‘soot line’: Destruction of presolar polycyclic aromatic hydrocarbons in the terrestrial planet-forming region of disks

Details The ‘soot line’: Destruction of presolar polycyclic aromatic hydrocarbons in the terrestrial planet-forming region of disks The ‘soot line’: Destruction of presolar polycyclic aromatic hydrocarbons in the terrestrial planet-forming region of disks

Jul 2010

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010adspr..46...44k&link_type=abstract

Advances in Space Research, Volume 46, Issue 1, p. 44-49.

Physics

6

Scientific paper

Interstellar material is highly processed when subjected to the physical conditions that prevail in the inner regions of protoplanetary disks, the potential birthplace of habitable planets. Polycyclic aromatic hydrocarbons (PAHs) are abundant in the interstellar medium, and they have also been observed in the disks around young stars, with evidence for some modification in the latter. Using a chemical model developed for sooting flames, we have investigated the chemical evolution of PAHs in warm (1000-2000 K) and oxygen-rich (C/O < 1) conditions appropriate for the region where habitable planets may eventually form. Our study focuses on (1) delineating the conditions under which PAHs will react and (2) identifying the key reaction pathways and reaction products characterizing this chemical evolution. We find that reactions with H, OH and O are the main pathways for destroying PAHs over disk timescale at temperatures greater than about 1000 K. In the process, high abundances of C2H2 persist over long timescales due to the kinetic inhibition of reactions that eventually drive the carbon into CO, CO2 and CH4. The thermal destruction of PAHs may thus be the cause of the abundant C2H2 that has been observed in disks. We propose that protoplanetary disks have a ‘soot line’, within which PAHs are irreversibly destroyed via thermally-driven reactions. The soot line will play an important role, analogous to that of the ‘snow line’, in the bulk carbon content of meteorites and habitable planets.

Affiliated with

Also associated with

No associations

Rating

The ‘soot line’: Destruction of presolar polycyclic aromatic hydrocarbons in the terrestrial planet-forming region of disks 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 The ‘soot line’: Destruction of presolar polycyclic aromatic hydrocarbons in the terrestrial planet-forming region of disks, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The ‘soot line’: Destruction of presolar polycyclic aromatic hydrocarbons in the terrestrial planet-forming region of disks will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1643532