Counter-streaming flows in a giant quiet-Sun filament observed in the extreme ultraviolet

摘要: Aim. The giant solar filament was visible on the surface from 2011 November 8–23. Multiwavelength data Solar Dynamics Observatory (SDO) were used to examine counter-streaming flows within spine of filament. Methods. We use two SDO instruments, Atmospheric Imaging Assembly (AIA) and Helioseismic Magnetic Imager (HMI), covering whole filament, which stretched over more than half a diameter. H α images Kanzelhohe (KSO) provide context information where is defined barbs are located. apply local correlation tracking (LCT) two-hour time series 16 AIA derive horizontal flow velocities To enhance contrast images, noise adaptive fuzzy equalization (NAFE) employed, allows us identify quantify in observe same cool plasma absorption both EUV images. Hence, directly related this material spine. In addition, we directional maps highlight flows. Results. detect time-lapse movies all four examined wavelength bands ( λ 171 Å, 193 304 211 Å). see that these persistent lasted for at least hours, although they became less prominent towards end series. Furthermore, by applying LCT clearly determine Å band, only minor indications with LCT, while band not detectable method. diverse morphology caused different processes, i.e., spectral line hydrogen helium continua, respectively. reach mean speeds about 0.5 km s −1 bands. highest identified up 2.5 . results averaged 90 minutes. Because sampling window has finite width, spatial degradation cannot be avoided leading lower estimates as compared feature or Doppler measurements. cover 15–20% area channel located central part Conclusions. Compared ground-based observations, absence seeing effects observations reveal even moderate image scale 0. ′′ 6 pixel Using enhancement technique, can detected quantified wavelengths. confirm omnipresence also quiet-Sun filaments.