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

• Published in: The Astrophysical Journal
• Main Authors: Murphy, R. P., Sasaki, M., Binns, W. R., Brandt, T. J., Hams, T., Israel, M. H., Labrador, A. W., Link, J. T., Mewaldt, R. A., Mitchell, J. W., Rauch, B. F., Sakai, K., Stone, E. C., Waddington, C. J., Walsh, N. E., Ward, J. E., Wiedenbeck, M. E.
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Astronomical Society 2016
• Subjects: Antarc*; Antarctica
• Online Access: https://authors.library.caltech.edu/71732/; https://authors.library.caltech.edu/71732/1/Murphy_2016_ApJ_831_148.pdf; https://authors.library.caltech.edu/71732/2/1608.08183v1.pdf; https://resolver.caltech.edu/CaltechAUTHORS:20161104-083553694

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_(-6^(+11)% material from massive stars and ~81% normal interstellar medium material with solar system abundances. The results also show a preferential acceleration of refractory elements (found in interstellar dust grains) by a factor of ~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.