Transition region counterpart of a moving magnetic feature
Armagh Observatory, College Hill, Armagh BT61 9DG, North Ireland, UK e-mail: firstname.lastname@example.org
2 National Center for Theoretical Sciences, Physics division, National Tsing-Hua University, Hsinchu, Taiwan
3 Astronomy Department, Yale University, New Haven, CT06511, USA
4 Indian Institute of Astrophysics, Koramangala, Bangalore 560034, India
Accepted: 30 August 2006
Context.While moving magnetic features have been studied extensively at the photospheric level, the effect they have on the upper atmosphere remains largely unknown, and it is this which we seek to address in this work.
Aims.In this work we aim to investigate the chromospheric and transition-region dynamics associated with a moving magnetic monopole by using spectral time-series and images.
Methods.Cross correlation was applied to images taken by different instruments and at different times in order to spatially correlate brightenings seen at transition region temperatures with moving magnetic features seen in magnetograms. We used wavelet analysis to examine and compare the periodicities of time-series signals in different regions.
Results.Oscillations with a multitude of frequencies are found in the chromospheric and transition-region brightenings associated with a moving magnetic monopole. The region of the brightenings shows a tendency to be blue-shifted when compared to the average motion of the entire field of view. The results indicate the presence of waves and/or flows carrying energy from the monopole to the higher atmosphere.
Conclusions.We studied the influence of a moving magnetic monopole, as recorded by magnetograms, up to transition region temperatures. This suggests that the magnetic monopole, despite being small, can influence dynamics in the upper atmospheric layers.
Key words: Sun: granulation / Sun: magnetic fields / Sun: oscillations / Sun: chromosphere / Sun: transition region
© ESO, 2006