Presentation on theme: "TRACE and RHESSI observations of failed eruption of magnetic flux rope and oscillating coronal loops Tomasz Mrozek Astronomical Institute University of."— Presentation transcript:
TRACE and RHESSI observations of failed eruption of magnetic flux rope and oscillating coronal loops Tomasz Mrozek Astronomical Institute University of Wrocław
The flare M6.2 GOES class N14 W61 RHESSI: entire event TRACE: 171 Å (several seconds cadence) 1600 Å (several cadence, decay phase) GOES SXI: several, saturated images SOHO LASCO: no CME reported
The flare GOES class M6.2 event connected with small (less than 10 4 km) arcade of loops. Clearly associated with the eruption of the magnetic structure.
Evolution of the eruption Initial phase connected with small brightenings in the HXRs 1 Fast evolution following the strongest HXR peak visible in keV range 2 Deceleration phase. Main front changes its shape. Side eruptions are observed keV H[km]
Higher in the corona… Above the erupting structure we observed the system of loops. These loops changes their height as the eruption evolves. The shape of the eruption front shows that „something” stopped the ejection. Side eruptions suggest that such breaking does not take place on the both sides of the high-lying loops
Interaction High-lying loops started to rise The end of the foremost eruption (and the end of the force driving the movement of the high-lying loops)
The same height before and after oscillations
Global oscillations of coronal loops Radial, transversal Change of radius One observation (Wang & Solanki 2004) Tangential, horizontal No change of radius About 20 observations reported by several authors
14 Jul 2004 event Observed oscillations are well described with the use of dumped sine function. Similar parameters to these obtained by Wang and Solanki (2004) Using method described by Nakariakov et al. (2001) we estimated magnetic field strength in the loop top to be equal G
CONCLUSIONS 1.Interesting events happen in the Bastille Day (14 Jul). 2.Relatively strong flare was not associated with a CME due to failed eruption of the magnetic structure. Can be this a rule for old active regions with well developed, high-lying systems of loops? 3.The main agent of the deceleration was the magnetic tension of loops lying above erupting structure. Estimated magnetic field in the loop top is G. 4.The second ever observation of radial oscillations of coronal loops was made. In this case we observed „the finger” that pulled loops – the magnetic structure ejected from below these loops.