Interplanetary Magnetic Flux Rope Observed at Ground Level by HAWC

Akiyama S, Alfaro R, Alvarez C, Angeles Camacho JR, Arteaga-Velazquez JC, Arunbabu KP, Avila Rojas D, Solares HAA, Belmont-Moreno E, Caballero-Mora KS, Capistran T, Carraminana A, Casanova S, Colin-Farias P, Cotti U, Cotzomi J, De La Fuente E, De Leon C, Hernandez RD, Espinoza C, Fraija N, Galvan-Gamez A, Garcia D, Garcia-Gonzalez JA, Garfias F, Gonzalez MM, Goodman JA, Harding JP, Hona B, Huang D, Hueyotl-Zahuantitla F, Huntemeyer P, Iriarte A, Joshi V, Kieda D, Kunde GJ, Lara A, Vargas HL, Luis-Raya G, Malone K, Martinez-Castro J, Matthews JA, Miranda-Romagnoli P, Moreno E, Nayerhoda A, Nellen L, Newbold M, Niembro T, Nieves-Chinchilla T, Noriega-Papaqui R, Perez-Perez EG, Preisser L, Rho CD, Ryan J, Salazar H, Salesa Greus F, Sandoval A, Springer RW, Torres I, Urena-Mena F, Villasenor L, Zepeda A (2020)

Publication Type: Journal article

Publication year: 2020


Book Volume: 905

Journal Issue: 1

DOI: 10.3847/1538-4357/abc344


We report the ground-level detection of a Galactic cosmic-ray (GCR) flux enhancement lasting similar to 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 local background, thus generating the ideal conditions to redirect and guide GCRs (in the similar to 8-60 GV rigidity range) along the magnetic field of the MFR. An important negative B-Z 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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Akiyama, S., Alfaro, R., Alvarez, C., Angeles Camacho, J.R., Arteaga-Velazquez, J.C., Arunbabu, K.P.,... Zepeda, A. (2020). Interplanetary Magnetic Flux Rope Observed at Ground Level by HAWC. Astrophysical Journal, 905(1).


Akiyama, S., et al. "Interplanetary Magnetic Flux Rope Observed at Ground Level by HAWC." Astrophysical Journal 905.1 (2020).

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