Radio Signature of the Strong Compression between a Streamer and a Coronal Hole Boundary
Informazioni aggiuntive
Autori
Aguilar-Rodriguez E.,
Vourlidas A.,
Corona-Romero P.,
Monstein C.,
Reeve W. D. .,
Romero-Hernandez E.,
Andrade-Mascote E.,
Villanueva-Hernandez P.,
Peralta-Mendoza I. A. .,
Perez-Leon J. E. .,
Perez-Tijerina E.
Tipo
Articolo pubblicato in rivista scientifica
Anno
2024
Lingua
Inglese
Abstract
We present evidence of the first detection of the radio signature at metric wavelengths of the strong compression between a helmet streamer (HS) and the boundary of a coronal hole (CH) using radio observations from the Callisto MEXICO-LANCE and ALASKA-HAARP systems and white-light observations obtained by the STEREO-A/COR1-COR2 coronagraphs. The event occurred very close to the Sun (∼3.4 solar radii) and produced an intense and unusually broad drifting radio feature at metric wavelengths after a downward-drifting band of emission related to a metric Type II radio burst. The compression is caused by the interaction between an expanding structure (coronal mass ejection/shock) and the HS against the CH boundary. Observations in white light show a sharp compressive feature that propagates radially outward, while STEREO-A/EUVI images show loop oscillations at the same position angle, indicating that the interaction occurs across a range of heights. The loop oscillations cease when the compressive front loses its sharp boundary. This transition indicates a reduction of the density compression at the front and the cessation of the radio emission.
Rivista
The Astrophysical Journal Letters
Volume
970
Numero
2
Mese
luglio
Pagina inizio
L35
