Corrugated Features in Coronal-mass-ejection-driven Shocks: A Discussion on the Predisposition to Particle Acceleration

Autor(es)

Paez, A. ^[1] ; Jatenco-Pereira, V ^[1] ; Falceta-Goncalves, D. ^[2] ; Opher, M. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Dept Astron, Rua Matao 1226, BR-05508090 Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, Escola Artes Ciencias & Humanidades, Rua Arlindo Bettio 1000, BR-03828000 Sao Paulo, SP - Brazil

^[3] Boston Univ, Dept Astron, 725 Commonwealth Ave, Boston, MA 02215 - USA

• Tipo de documento: Artigo Científico
• Fonte: ASTROPHYSICAL JOURNAL; v. 879, n. 2 JUL 10 2019.
• Citações Web of Science: 0

Resumo

The study of the acceleration of particles is an essential element of research in heliospheric science. Here, we discuss the predisposition to the particle acceleration around shocks driven by coronal mass ejections (CMEs) with corrugated wave-like features. We adopt these attributes on shocks formed from disturbances due to the bimodal solar wind, CME deflection, irregular CME expansion, and the ubiquitous fluctuations in the solar corona. In order to understand the role of a wavy shock in particle acceleration, we define three initial smooth shock morphologies each associated with a fast CME. Using polar Gaussian profiles we model these shocks in the low corona. We establish the corrugated appearance on smooth shock by using combinations of wave-like functions that represent the disturbances from the medium and CME piston. For both shock types, smooth and corrugated, we calculate the shock normal angles between the shock normal and the radial upstream coronal magnetic field in order to classify the quasi-parallel and quasi-perpendicular regions. We consider that corrugated shocks are predisposed to different processes of particle acceleration due to irregular distributions of shock normal angles around the shock. We suggest that disturbances due to CME irregular expansion may be a decisive factor in origin of particle acceleration. Finally, we regard that accepting these features on shocks may be the starting point for investigating some questions regarding the sheath and shock, like downstream jets, instabilities, shock thermalization, shock stability, and injection particle processes. (AU)

• Processo FAPESP: 13/10559-5 - Investigação de fenômenos de altas energias e plasmas astrofísicos: teoria, simulações numéricas, observações e desenvolvimento de instrumentação para o Cherenkov Telescope Array (CTA)
• Beneficiário: Elisabete Maria de Gouveia Dal Pino
• Linha de fomento: Auxílio à Pesquisa - Temático