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Title: EXTREME-ULTRAVIOLET MULTI-WAVELENGTH OBSERVATIONS OF QUASI-PERIODIC PULSATIONS IN A SOLAR POST-FLARE CUSP-SHAPE LOOP WITH SDO/AIA

Journal Article · · Astrophysical Journal
 [1]; ;  [2]
  1. Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Science, Beijing 100012 (China)
  2. National Astronomical Observatories/Yunnan Observatory, Chinese Academy of Sciences, Kunming 650011 (China)

We present extreme-ultraviolet multi-wavelength observations with the SDO/AIA instruments of quasi-periodic pulsations (QPPs) propagating along a cusp-shaped loop formed after an M2.2 flare on the Sun. Our motivation is to detect whether there were slow-mode magnetoacoustic waves propagating along its protruding flux tube. To this end, with fast Fourier transform we extract the short (<3 minutes) and long (>3 minutes) period components of the QPPs from time-space diagrams of the tube slices. We find that velocity differences did exist among the short/long-period components of different wavelengths, but only one event in the long-period ones showed they were greater than the measurement errors (e.g., 65 km s{sup -1}), which were 330 km s{sup -1} detected in 171 A, 590 km s{sup -1} in 211 A, and 180 km s{sup -1} in 304 A. The intensity modulation in all wavelengths is found to be very large, e.g., {approx}60% of the emission trend for an event in the 171 A passband, which would be an order of magnitude higher than the perturbation of the plasma density in the slow-mode magnetoacoustic waves. Moreover, only the QPPs with upward velocities of 50-300 km s{sup -1} are found in the tube, and the downward ones of several tens of kilometers are never unambiguously detected. Therefore, most of the QPP events under study were likely the episodic outflows along the tube, and the one with a supersonic speed of 590 km s{sup -1} may be a kink wave.

OSTI ID:
22039312
Journal Information:
Astrophysical Journal, Vol. 754, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
Country of Publication:
United States
Language:
English