Galactic Cosmic Ray Origins and OB Associations: Evidence from SuperTIGER Observations of Elements _(26)Fe through _(40)Zr
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 r...
Published in: | The Astrophysical Journal |
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Main Authors: | , , , , , , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
American Astronomical Society
2016
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Subjects: | |
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 |
Summary: | 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. |
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