The 11B/ 10B Ratio of Local Interstellar Diffuse Clouds

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

28

Ism: Dust, Extinction, Ism: Abundances, Ultraviolet: Ism

Scientific paper

The isotopic ratio 11B/10B of gas in diffuse interstellar clouds toward zeta Oph, kappa Ori, and delta Sco is measured using HST/Goddard High Resolution Spectrograph echelle spectra of the B II 1362 Angstroms line. To within the errors of measurement, the three lines of sight give identical results for a mean value of 11B/10B = 3.4 +/- 0.7, a value quite similar to the solar system ratio of 4.05. These results show that the latter value is not highly anomalous and that a ratio higher than 2.5, as predicted for boron produced from spallation reactions controlled by high-energy cosmic rays, most probably requires a general explanation. The observed ratio is consistent with additional boron production either by spallation by low-energy ("Orion") cosmic rays or by neutrino-induced spallation of carbon in Type II supernovae. The total abundance of B in the diffuse clouds is a factor of 5 less than the meteoritic value. This depletion of B is consistent with that found for Cu and Ga, two elements with a condensation temperature similar to B.

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

The 11B/ 10B Ratio of Local Interstellar Diffuse Clouds 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 11B/ 10B Ratio of Local Interstellar Diffuse Clouds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The 11B/ 10B Ratio of Local Interstellar Diffuse Clouds will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1223214

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