Observation of Anisotropy of TeV Cosmic Rays with Two Years of HAWC
Document Type
Article
Publication Date
9-20-2018
Abstract
© 2018. The American Astronomical Society. All rights reserved. After two years of operation, the High-Altitude Water Cherenkov (HAWC) Observatory has analyzed the TeV cosmic-ray sky over an energy range between 2.0 and 72.8 TeV. Like other detectors in the northern and southern hemispheres, HAWC observes an energy-dependent anisotropy in the arrival direction distribution of cosmic rays. This anisotropy is dominated by a dipole moment with phase in R.A. α ≈ 40° and amplitude that slowly rises in relative intensity from 8 ×10-4 at 2 TeV to 14 ×10-4 around 30 TeV, above which the dipole decreases in strength. A significant large-scale (> 60° in angular extent) signal is also observed in the quadrupole and octupole moments, and significant small-scale features are also present, with locations and shapes consistent with previous observations. Compared to previous measurements in this energy range, the HAWC cosmic-ray sky maps improve on the energy resolution and fit precision of the anisotropy. These data can be used in an effort to better constrain local cosmic-ray accelerators and the intervening magnetic fields.
Publication Title
Astrophysical Journal
Recommended Citation
Abeysekara, A.,
Alfaro, R.,
Alvarez, C.,
Alvarez, J.,
Arceo, R.,
Arteaga-Velázquez, J.,
Rojas, D.,
Solares, H.,
Becerril, A.,
Belmont-Moreno, E.,
Benzvi, S.,
Bernal, A.,
Braun, J.,
Caballero-Mora, K.,
Capistrán, T.,
Carraminana, A.,
Casanova, S.,
Castillo, M.,
Cotti, U.,
Cotzomi, J.,
León, C.,
Fuente, E.,
Hernandez, R.,
Dichiara, S.,
Dingus, B.,
Duvernois, M.,
Diaz-Vélez, J.,
Engel, K.,
Fiorino, D.,
Fraija, N.,
Garcia-González, J.,
&
Garfias, F.
(2018).
Observation of Anisotropy of TeV Cosmic Rays with Two Years of HAWC.
Astrophysical Journal,
865(1).
http://doi.org/10.3847/1538-4357/aad90c
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/14148