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arXiv · 1608.08183

Galactic Cosmic Ray Origins and OB Associations: Evidence from SuperTIGER Observations of Elements $_{26}$Fe through $_{40}$Zr

R. P. Murphy·M. Sasaki·W. R. Binns·T. J. Brandt·T. Hams·M. H. Israel·A. W. Labrador·J. T. Link·R. A. Mewaldt·J. W. Mitchell·B. F. Rauch·K. Sakai·E. C. Stone·C. J. Waddington·N. E. Walsh·J. E. Ward·M. E. Wiedenbeck
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Abstract

We report abundances of elements from $_{26}$Fe to $_{40}$Zr in the cosmic radiation measured by the SuperTIGER (Trans-Iron Galactic Element Recorder) instrument during 55 days of exposure on a long-duration balloon flight over Antarctica. These observations resolve elemental abundances in this charge range with single-element resolution and good statistics. These results support a model of cosmic-ray origin in which the source material consists of a mixture of 19$^{+11}_{-6}$\% material from massive stars and $\sim$81\% normal interstellar medium (ISM) material with solar system abundances. The results also show a preferential acceleration of refractory elements (found in interstellar dust grains) by a factor of $\sim$4 over volatile elements (found in interstellar gas) ordered by atomic mass (A). Both the refractory and volatile elements show a mass-dependent enhancement with similar slopes.

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R. P. Murphy, M. Sasaki, W. R. Binns, T. J. Brandt, T. Hams, M. H. Israel, A. W. Labrador, J. T. Link, R. A. Mewaldt, J. W. Mitchell, B. F. Rauch, K. Sakai, E. C. Stone, C. J. Waddington, N. E. Walsh, J. E. Ward, M. E. Wiedenbeck. 2016-08-29. Galactic Cosmic Ray Origins and OB Associations: Evidence from SuperTIGER Observations of Elements $_{26}$Fe through $_{40}$Zr. https://doi.org/10.3847/0004-637x%2F831%2F2%2F148

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