Search Publications
Analysis of photospheric magnetic fields in AR 12546: a case study
Abdelkawy, Ali G. A.; Shaltout, Abdelrazek M. K.
We investigate high-resolution observations with the spectropolarimeter (SP) aboard the Hinode satellite of the Solar Optical Telescope (SOT) of a positive polarity sunspot of an active region (AR) (NOAA 12546). We present a case study for the properties of the thermal, magnetic field, and plasma flows as a function of the optical depth from the i…
Kelvin–Helmholtz instability in an active region jet observed with Hinode
Srivastava, A. K.; Zhelyazkov, I.; Chandra, R.
Over past ten years a variety of jet-like phenomena were detected in the solar atmosphere, including plasma ejections over a range of coronal temperatures being observed as extreme ultraviolet (EUV) and X-ray jets. We study the possibility for the development of Kelvin–Helmholtz (KH) instability of transverse magnetohydrodynamic (MHD) waves travel…
Improved SOT (Hinode mission) high resolution solar imaging observations: 2—Photometric properties of sunspot umbral dots
Koutchmy, S.; Adjabshirizadeh, A.; Goodarzi, H.
The origin and evolution of solar sunspots in deep photospheric layers are not yet well understood. The case of a quasi-symmetric single mature sunspot near the solar centre is selected for analysis. We use the best available observations of the partial Sun free of turbulent Earth atmospheric effects from the Solar Optical Telescope (SOT) onboard …
The quasi-periodic behavior of recurrent jets caused by emerging magnetic flux
Yang, J. Y.; Liang, H. F.; Jiang, Y. C. +2 more
A series of recurring jets occurred at the edge of an active region NOAA 11459 on 2012 April 20, and they were observed simultaneously at EUV and soft X-ray wavelengths. They also were sometimes associated with a hard X-ray source at the base region. The jets might have resulted from magnetic reconnection between the newly emerging flux and the pr…
Improved SOT (Hinode mission) high resolution solar imaging observations
Koutchmy, S.; Adjabshirizadeh, A.; Goodarzi, H.
We consider the best today available observations of the Sun free of turbulent Earth atmospheric effects, taken with the Solar Optical Telescope (SOT) onboard the Hinode spacecraft. Both the instrumental smearing and the observed stray light are analyzed in order to improve the resolution. The Point Spread Function (PSF) corresponding to the blue …
Power spectrum analysis of limb and disk spicule using Hinode Ca H-line broadband filter
Tavabi, E.
We present observations of a solar quiet region obtained using the Hinode Solar Optical telescope (SOT) in the Ca II H-line with broadband filter taken on November 2006. We study off-limb and on-disk spicules to find a counterpart of the limb spicule on the disk. This investigation shows a strong correspondence between the limb and near limb spicu…
Observation of kink waves and their reconnection-like origin in solar spicules
Ebadi, H.; Ghiassi, M.
We analyze the time series of Ca II H-line obtained from Hinode/SOT on the solar limb. We follow three cases of upwardly propagating kink waves along a spicule and inverted Y-shaped structures at the cusp of it. The time-distance analysis shows that the axis of spicule undergos quasi-periodic transverse displacement at different heights from the p…
Oscillations in solar jets observed with the SOT of Hinode: viscous effects during reconnection
Koutchmy, S.; Tavabi, E.
Transverse oscillatory motions and recurrence behavior in the chromospheric jets observed by Hinode/SOT are studied. A comparison is considered with the behavior that was noticed in coronal X-ray jets observed by Hinode/XRT. A jet like bundle observed at the limb in Ca II H line appears to show a magnetic topology that is similar to X-ray jets (i.…
On vortex motion in chromospheric network boundaries
Tavabi, E.
A large percent of spicules shows a surge-like behavior on the solar limb, supporting a multi-component model with twisted threads. The counterpart of limb spicules foot-points is investigated on the disk, and this re-examination indicates that the interpretation of transverse motion of off-limb spicules could directly be related to rotational mot…
Evidences to the pulse like origin of double spicules based on Hinode/SOT observations
Ebadi, H.
We analyze the time series of Hα line obtained from Hinode/SOT on the solar limb. The wavelet analysis shows that there are nice correlations between dynamical properties of the two parts of a double spicule. The dominant periods for height variations are estimated ∼90 and ∼180 s. The length of two parts of the spicule oscillates with the period o…