134 research outputs found
Ca II K Spectral Study of an Emerging Flux Region using Domeless Solar Telescope in Hida Observatory
A cooperative observation with Hida observatory and Hinode satellite was
performed on an emerging flux region. The successive Ca II K spectro-heliograms
of the emerging flux region were taken by the Domeless Solar Telescope of Hida
observatory. Hinode observed the emerging flux region with Ca II H and Fe I
Stokes IQUV filtergrams. In this study, detailed dynamics and temporal
evolution of the magnetic flux emergence was studied observationally. The event
was first detected in the photospheric magnetic field signals. 3 minutes later,
the horizontal expansion of the dark area was detected. And then, 7 minutes
later than the horizontal expansion, the emerging loops were detected with the
maximal rise speed of 2.1 km/s at chromospheric heights. The observed dynamics
of emerging magnetic flux from the photosphere to the upper chromosphere is
well consistent with the results of previous simulation works. The gradual
rising phase of flux tubes with a weak magnetic strength was confirmed by our
observation.Comment: 14 pages, 7 figure
Fast-Ion-Diagnostics for CHS Experiment
Fast-ion-diagnostics have played an important role in investigating issues related to fast ion orbits and fast-ion-driven MHD instabilities in CHS experiments. The fast-ion diagnostics employed in CHS are reviewed and experimentally obtained knowledge is summarized
Spicule Dynamics over Plage Region
We studied spicular jets over a plage area and derived their dynamic
characteristics using Hinode Solar Optical Telescope (SOT) high-resolution
images. The target plage region was near the west limb of the solar disk. This
location permitted us to study the dynamics of spicular jets without the
overlapping effect of spicular structures along the line of sight.
In this work, to increase the ease with which we can identify spicules on the
disk, we applied the image processing method `MadMax' developed by Koutchmy et
al. (1989). It enhances fine, slender structures (like jets), over a diffuse
background. We identified 169 spicules over the target plage. This sample
permits us to derive statistically reliable results regarding spicular
dynamics.
The properties of plage spicules can be summarized as follows: (1) In a plage
area, we clearly identified spicular jet features. (2) They were shorter in
length than the quiet region limb spicules, and followed ballistic motion under
constant deceleration. (3) The majority (80%) of the plage spicules showed the
cycle of rise and retreat, while 10% of them faded out without a complete
retreat phase. (4) The deceleration of the spicule was proportional to the
velocity of ejection (i.e. the initial velocity).Comment: 12 pages, 9 figures, accepted for publication in PAS
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