Pregled bibliografske jedinice broj: 50460
On the magnetic field evolution during a radio pulsation event
On the magnetic field evolution during a radio pulsation event // Ninth European Meeting on Solar Physics: Magnetic Fields and Solar Processes / Wilson, A. (ur.).
Noordwijk: European Space Agency, 1999. (poster, međunarodna recenzija, sažetak, znanstveni)
CROSBI ID: 50460 Za ispravke kontaktirajte CROSBI podršku putem web obrasca
Naslov
On the magnetic field evolution during a radio pulsation event
Autori
Aurass, Henry ; Hofmann, Axel ; Vršnak, Bojan ; Ruždjak, Vladimir
Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni
Izvornik
Ninth European Meeting on Solar Physics: Magnetic Fields and Solar Processes
/ Wilson, A. - Noordwijk : European Space Agency, 1999
Skup
Ninth Meeting of the Solar Physics Section of the Joint Astrophysics Division of the European Physical Socity (EPS) and of the European Astronomical Society (EAS)
Mjesto i datum
Firenca, Italija, 12.09.1999. - 18.09.1999
Vrsta sudjelovanja
Poster
Vrsta recenzije
Međunarodna recenzija
Sažetak
We reanalyzed radio observations, magnetograms, H&alpha data, and Yohkoh soft X-ray images of NOAA AR 7792 for the 25 October 1994 flare event. The active region is characterized by sigmoid shaped soft X-ray loop systems. Force-free extrapolated magnetic field line maps have been calculated for different height ranges of the active region corona. Our aim was to identify those parts of the field line maps which become activated during the flare. We find evidence for at least three interacting acceleration sites of nonthermal electrons. Two of them are situated within a sheared field arcade which forms two expanding ribbons in flaring.
A third acceleration site is associated with an area of emerging magnetic flux of parasitic polarity near the main sunspot of the active region. At this site, soft X-ray jet activity was seen already days before the flare. A confined flare topology is identified there in heights below 10000 km. The arcade flare and the confined flare regions get more and more interacting due to
the arcade flare ribbons expansion. In this interaction stage a reconnection process in the confined flare structure seems to become more and more driven. This leads to a quasiperiodic injection of streams of nonthermal electrons observed as a decimetric - metric radio pulsation event. The analysis illuminates the association between the evolution of the soft X-ray loop morphology and the dynamics of nonthermal electron acceleration during this event.
Izvorni jezik
Engleski
Znanstvena područja
Fizika
