The11B/10B Ratio of Local Interstellar Diffuse Clouds

• DOI: 10.1086/305235
• Publication Date: 2002-07-26T18:50:31Z
• Authors: David L. Lambert; Yaron Sheffer; S. R. Federman; Jason A. Cardelli; Ulysses J. Sofia; David C. Knauth
• Keywords: Isotopes of boron

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