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Figure 1: MDI image showing the position of active regions on October 14, 1999. An impulsive X1/1N flare occured in region 8371 at 0858 UT. |
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Figure 2:
Series of images built from the
H![]() |
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Figure 3:
Running difference images in H![]() |
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Figure 4: Position of the main radio emitting regions A, B, C, D, E and F. Different symbols correspond to different observing frequencies: squares to 164 MHz, triangles to 236 MHz, crosses to 327 MHz and circles to 410 MHz. |
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Figure 5: Flux versus time of the event at the different observing frequencies of the NRH. After a relatively quiet period with only weak bursts at low frequencies, the flux raises by a few orders of magnitude shortly after 08:58 UT. This outburst that lasts a few minutes is then followed by relatively stable or low rising continua at the different frequencies. |
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Figure 6: Composite spectrum in the band of 1 MHz-7.6 GHz, observated by Wind/Waves (1-10 MHz), Porto (150-650 MHz), Ondrejov (0.8-4.5 GHz) and Beijing (5.2-7.6 GHz). |
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Figure 7: Peak brightness temperature time at 410 for small boxes encompassing sources A and D. The only relevant outbursts are seen a few seconds after 0858 UT, nearly simultaneous at the two positions (brightness at D starts rising some 20 to 30 s later than at A). |
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Figure 8: (From the top) Panel 1: flux evolution of sources C at 236 MHz. Panels 2 and 3: flux evolution of sources D and E at 164 MHz and 327 MHz. The broad band continuum is associated with D and the bursty emission with E. |
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Figure 9: Flux and location evolution of source F. At about 08:58:30 a new source is seen in radio images at 164 MHz. This source shows a displacement toward the north with an apparent speed about 6000 km s-1. |
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Figure 10: After 08:59:23 UT the D source becomes extremely elongated in the direction shown by the line in the 410 MHz image in the upper right corner. The brightness profiles taken along this line show an excess brightness that moves with an apparent velocity about 1500 km s-1. |
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Figure 11: LASCO images of the CME showing its progression. A series of key figures are indicated in the C2 image at 0926:05 UT. The arrow in C3 images indicates a feature that seems to correspond to K3 that expands at a different rate to the rest of the CME. |
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Figure 12: Height-time plot for features K1 and K3 in the CME. |
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Figure 13: Decelerated CME? The circle indicated by the arrow shows the extrapolated position of the CME leading edge at this time. No evidence for the CME is seen in the LASCO image. |
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Figure 14: Left: Yohkoh/SXT image of the active complex (12:42 UT) superimposed with the position of the radio sources observed with the NRH. Right: Same SXT image overlaid by magnetic field lines calculated from the linear force-free field extrapolation of the SOHO/MDI magnetogram (08:00 UT). The thin parallelogram shows a portion only of the magnetogram used for the extrapolation. Units are in arcsec. |
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Figure 15:
Top left: SOHO/MDI magnetogram (grey levels) overlaid with the
positions of observed radio sources (yellow) and some calculated magnetic
field lines. Pink/blue contours stand for
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