Discrepant hardening observed in cosmic-ray elemental spectra
The balloon-borne Cosmic Ray Energetics And Mass experiment launched five times from Antarctica has achieved a cumulative flight duration of about 156 days above 99.5% of the atmosphere. The instrument is configured with complementary and redundant particle detectors designed to extend direct measur...
Published in: | The Astrophysical Journal |
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Online Access: | http://hdl.handle.net/11365/20546 https://doi.org/10.1088/2041-8205/714/1/L89 |
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ftunivsiena:oai:usiena-air.unisi.it:11365/20546 2024-04-14T08:03:42+00:00 Discrepant hardening observed in cosmic-ray elemental spectra H. S. AHN P. ALLISON BAGLIESI, MARIA GRAZIA J. J. BEATTY BIGONGIARI, GABRIELE J. T. CHILDERS N. B. CONKLIN S. COUTU M. A. DUVERNOIS O. GANEL J. H. HAN J. A. JEON K. C. KIM M. H. LEE L. LUTZ MAESTRO, PAOLO A. MALININ MARROCCHESI, PIER SIMONE S. MINNICK S. I. MOGNET J. NAM S. NAM S. L. NUTTER I. H. PARK N. H. PARK E. S. SEO R. SINA J. WU J. YANG Y. S. YOON ZEI, RICCARDO S. Y. ZINN H. S., Ahn P., Allison Bagliesi, MARIA GRAZIA J. J., Beatty Bigongiari, Gabriele J. T., Childer N. B., Conklin S., Coutu M. A., Duvernoi O., Ganel J. H., Han J. A., Jeon K. C., Kim M. H., Lee L., Lutz Maestro, Paolo A., Malinin Marrocchesi, PIER SIMONE S., Minnick S. I., Mognet J., Nam S., Nam S. L., Nutter I. H., Park N. H., Park E. S., Seo R., Sina J., Wu J., Yang Y. S., Yoon Zei, Riccardo S. Y., Zinn 2010 STAMPA http://hdl.handle.net/11365/20546 https://doi.org/10.1088/2041-8205/714/1/L89 eng eng info:eu-repo/semantics/altIdentifier/wos/WOS:000276971300018 volume:714 issue:1, part 2 firstpage:L89 lastpage:L93 numberofpages:5 journal:THE ASTROPHYSICAL JOURNAL LETTERS http://hdl.handle.net/11365/20546 doi:10.1088/2041-8205/714/1/L89 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-77950938657 info:eu-repo/semantics/closedAccess astroparticle physic cosmic ray balloon supernovae acceleration info:eu-repo/semantics/article 2010 ftunivsiena https://doi.org/10.1088/2041-8205/714/1/L89 2024-03-21T15:56:21Z The balloon-borne Cosmic Ray Energetics And Mass experiment launched five times from Antarctica has achieved a cumulative flight duration of about 156 days above 99.5% of the atmosphere. The instrument is configured with complementary and redundant particle detectors designed to extend direct measurements of cosmic-ray composition to the highest energies practical with balloon flights. All elements from protons to iron nuclei are separated with excellent charge resolution. Here, we report results from the first two flights of ∼70 days, which indicate hardening of the elemental spectra above ∼200 GeV/nucleon and a spectral difference between the two most abundant species, protons and helium nuclei. These results challenge the view that cosmic-ray spectra are simple power laws below the so-called knee at ∼10^15 eV. This discrepant hardening may result from a relatively nearby source, or it could represent spectral concavity caused by interactions of cosmic rays with the accelerating shock. Other possible explanations should also be investigated. Article in Journal/Newspaper Antarc* Antarctica Università degli Studi di Siena: USiena air The Astrophysical Journal 714 1 L89 L93 |
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Open Polar |
collection |
Università degli Studi di Siena: USiena air |
op_collection_id |
ftunivsiena |
language |
English |
topic |
astroparticle physic cosmic ray balloon supernovae acceleration |
spellingShingle |
astroparticle physic cosmic ray balloon supernovae acceleration H. S. AHN P. ALLISON BAGLIESI, MARIA GRAZIA J. J. BEATTY BIGONGIARI, GABRIELE J. T. CHILDERS N. B. CONKLIN S. COUTU M. A. DUVERNOIS O. GANEL J. H. HAN J. A. JEON K. C. KIM M. H. LEE L. LUTZ MAESTRO, PAOLO A. MALININ MARROCCHESI, PIER SIMONE S. MINNICK S. I. MOGNET J. NAM S. NAM S. L. NUTTER I. H. PARK N. H. PARK E. S. SEO R. SINA J. WU J. YANG Y. S. YOON ZEI, RICCARDO S. Y. ZINN Discrepant hardening observed in cosmic-ray elemental spectra |
topic_facet |
astroparticle physic cosmic ray balloon supernovae acceleration |
description |
The balloon-borne Cosmic Ray Energetics And Mass experiment launched five times from Antarctica has achieved a cumulative flight duration of about 156 days above 99.5% of the atmosphere. The instrument is configured with complementary and redundant particle detectors designed to extend direct measurements of cosmic-ray composition to the highest energies practical with balloon flights. All elements from protons to iron nuclei are separated with excellent charge resolution. Here, we report results from the first two flights of ∼70 days, which indicate hardening of the elemental spectra above ∼200 GeV/nucleon and a spectral difference between the two most abundant species, protons and helium nuclei. These results challenge the view that cosmic-ray spectra are simple power laws below the so-called knee at ∼10^15 eV. This discrepant hardening may result from a relatively nearby source, or it could represent spectral concavity caused by interactions of cosmic rays with the accelerating shock. Other possible explanations should also be investigated. |
author2 |
H. S., Ahn P., Allison Bagliesi, MARIA GRAZIA J. J., Beatty Bigongiari, Gabriele J. T., Childer N. B., Conklin S., Coutu M. A., Duvernoi O., Ganel J. H., Han J. A., Jeon K. C., Kim M. H., Lee L., Lutz Maestro, Paolo A., Malinin Marrocchesi, PIER SIMONE S., Minnick S. I., Mognet J., Nam S., Nam S. L., Nutter I. H., Park N. H., Park E. S., Seo R., Sina J., Wu J., Yang Y. S., Yoon Zei, Riccardo S. Y., Zinn |
format |
Article in Journal/Newspaper |
author |
H. S. AHN P. ALLISON BAGLIESI, MARIA GRAZIA J. J. BEATTY BIGONGIARI, GABRIELE J. T. CHILDERS N. B. CONKLIN S. COUTU M. A. DUVERNOIS O. GANEL J. H. HAN J. A. JEON K. C. KIM M. H. LEE L. LUTZ MAESTRO, PAOLO A. MALININ MARROCCHESI, PIER SIMONE S. MINNICK S. I. MOGNET J. NAM S. NAM S. L. NUTTER I. H. PARK N. H. PARK E. S. SEO R. SINA J. WU J. YANG Y. S. YOON ZEI, RICCARDO S. Y. ZINN |
author_facet |
H. S. AHN P. ALLISON BAGLIESI, MARIA GRAZIA J. J. BEATTY BIGONGIARI, GABRIELE J. T. CHILDERS N. B. CONKLIN S. COUTU M. A. DUVERNOIS O. GANEL J. H. HAN J. A. JEON K. C. KIM M. H. LEE L. LUTZ MAESTRO, PAOLO A. MALININ MARROCCHESI, PIER SIMONE S. MINNICK S. I. MOGNET J. NAM S. NAM S. L. NUTTER I. H. PARK N. H. PARK E. S. SEO R. SINA J. WU J. YANG Y. S. YOON ZEI, RICCARDO S. Y. ZINN |
author_sort |
H. S. AHN |
title |
Discrepant hardening observed in cosmic-ray elemental spectra |
title_short |
Discrepant hardening observed in cosmic-ray elemental spectra |
title_full |
Discrepant hardening observed in cosmic-ray elemental spectra |
title_fullStr |
Discrepant hardening observed in cosmic-ray elemental spectra |
title_full_unstemmed |
Discrepant hardening observed in cosmic-ray elemental spectra |
title_sort |
discrepant hardening observed in cosmic-ray elemental spectra |
publishDate |
2010 |
url |
http://hdl.handle.net/11365/20546 https://doi.org/10.1088/2041-8205/714/1/L89 |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000276971300018 volume:714 issue:1, part 2 firstpage:L89 lastpage:L93 numberofpages:5 journal:THE ASTROPHYSICAL JOURNAL LETTERS http://hdl.handle.net/11365/20546 doi:10.1088/2041-8205/714/1/L89 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-77950938657 |
op_rights |
info:eu-repo/semantics/closedAccess |
op_doi |
https://doi.org/10.1088/2041-8205/714/1/L89 |
container_title |
The Astrophysical Journal |
container_volume |
714 |
container_issue |
1 |
container_start_page |
L89 |
op_container_end_page |
L93 |
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