The shadowing of cosmic ray primaries by the moon and sun was observed by the MINOS far detector at a depth of 2070 mwe using 83.54 million cosmic ray muons accumulated over 1857.91 live-days. The shadow of the moon was detected at the 5.6 σ level and the shadow of the sun at the 3.8 σ level using a log-likelihood search in celestial coordinates. The moon shadow was used to quantify the absolute astrophysical pointing of the detector to be 0.17 ± 0.12°. Hints of interplanetary magnetic field effects were observed in both the sun and moon shadow.
|Original language||English (US)|
|Number of pages||10|
|State||Published - Jan 2011|
Bibliographical noteFunding Information:
We thank the Fermilab staff and the technical staffs of the participating institutions for their vital contributions. This work was supported by the U.S. Department of Energy, the U.S. National Science Foundation, the U.K. Science and Technologies Facilities Council, the State and University of Minnesota, the Office of Special Accounts for Research Grants of the University of Athens, Greece, FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo), CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) in Brazil. We gratefully acknowledge the Minnesota Department of Natural Resources for their assistance and for allowing us access to the facilities of the Soudan Underground Mine State Park and the crew of the Soudan Underground Physics laboratory for their tireless work in building and operating the MINOS detector.
- Cosmic rays
- Interplanetary magnetic field
- Moon shadow
- Sun shadow