Slow magnetoacoustic waves in coronal loops: EIT and TRACE

Details Slow magnetoacoustic waves in coronal loops: EIT and TRACE Slow magnetoacoustic waves in coronal loops: EIT and TRACE

May 2001

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2001a%26a...370..591r&link_type=abstract

Astronomy and Astrophysics, v.370, p.591-601 (2001)

Astronomy and Astrophysics

Astrophysics

103

Sun: Activity, Sun: Corona, Sun: Oscillations, Sun: Uv Radiation, Mhd, Waves

Scientific paper

On May 13, 1998 the EIT (Extreme ultraviolet Imaging Telescope) on board of SoHO (Solar and Heliospheric Observatory) and TRACE (Transition Region And Coronal Explorer) instruments produced simultaneous high cadence image sequences of the same active region (AR 8218). TRACE achieved a 25 s cadence in the Fe Ix (171 Å) bandpass while EIT achieved a 15 s cadence (operating in ``shutterless mode'', SoHO JOP 80) in the Fe Xii (195 Å) bandpass. These high cadence observations in two complementary wavelengths have revealed the existence of weak transient disturbances in an extended coronal loop system. These propagating disturbances (PDs) seem to be a common phenomenon in this part of the active region. The disturbances originate from small scale brightenings at the footpoints of the loops and propagate along the loops. The projected propagation speeds roughly vary between 65 and 150 km s-1 for both instruments which is close to and below the expected sound speed in the coronal loops. The measured slow magnetoacoustic propagation speeds seem to suggest that the transients are sound (or slow) wave disturbances. This work differs from previous studies in the sense that it is based on a multi-wavelength observation of an entire loop bundle at high cadence by two EUV imagers. The observation of sound waves along the same path shows that they propagate along the same loop, suggesting that loops contain sharp temperature gradients and consist of either concentric shells or thin loop threads, at different temperatures.

Affiliated with

Also associated with

No associations

Rating

Slow magnetoacoustic waves in coronal loops: EIT and TRACE does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Slow magnetoacoustic waves in coronal loops: EIT and TRACE, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Slow magnetoacoustic waves in coronal loops: EIT and TRACE will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1266280