Interplanetary magnetic flux rope observed at ground level by HAWC
Abstract
We report the ground-level detection of a Galactic Cosmic-Ray (GCR) flux enhancement lasting 17 hr and associated with the passage of a magnetic flux rope (MFR) over the Earth. The MFR was associated with a slow Coronal Mass Ejection (CME) caused by the eruption of a filament on 2016 October 9. Due to the quiet conditions during the eruption and the lack of interactions during the interplanetary CME transport to the Earth, the associated MFR preserved its configuration and reached the Earth with a strong magnetic field, low density, and a very low turbulence level compared to the local background, thus generating the ideal conditions to redirect and guide GCRs (in the 8 to 60 GV rigidity range) along the magnetic field of the MFR. An important negative component inside the MFR caused large disturbances in the geomagnetic field and a relatively strong geomagnetic storm. However, these disturbances are not the main factors behind the GCR enhancement. Instead, we found that the major factor was the alignment between the MFR axis and the asymptotic direction of the observer.
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Cite
@article{arxiv.2101.03243,
title = {Interplanetary magnetic flux rope observed at ground level by HAWC},
author = {S. Akiyama and R. Alfaro and C. Alvarez and J. R. Angeles Camacho and J. C. Arteaga-Velázquez and K. P. Arunbabu and D. Avila Rojas and H. A. Ayala Solares and E. Belmont-Moreno and K. S. Caballero-Mora and T. Capistrán and A. Carramiñana and S. Casanova and P. Colin-Farias and U. Cotti and J. Cotzomi and E. De la Fuente and C. de León and R. Diaz Hernandez and C. Espinoza and N. Fraija and A. Galván-Gámez and D. Garcia and J. A. García-González and F. Garfias and M. M. González and J. A. Goodman and J. P. Harding and B. Hona and D. Huang and F. Hueyotl-Zahuantitla and P. Huntemeyer and A. Iriarte and V. Joshi and D. Kieda and G. J. Kunde and A. Lara and H. León Vargas and G. Luis-Raya and K. Malone and J. Martínez-Castro and J. A. Matthews and P. Miranda-Romagnoli and E. Moreno and A. Nayerhoda and L. Nellen and M. Newbold and T. Niembro and T. Nieves-Chinchilla and R. Noriega-Papaqui and E. G. Pérez-Pérez and L. Preisser and C. D. Rho and J. Ryan and H. Salazar and F. Salesa Greus and A. Sandoval and R. W. Springer and I. Torres and F. Ureña-Mena and L. Villaseñor and A. Zepeda},
journal= {arXiv preprint arXiv:2101.03243},
year = {2021}
}