In order to better understand the possibility of coronal heating by MHD waves, we analyze Fe xii 195.12 Å data observed with EUV Imaging Spectrometer (EIS) onboardHinode. We performed a Fourier analysis of EUV intensity and Doppler velocity time series data in the active region corona. Notable intensity and Doppler velocity oscillations were found for two moss regions out of the five studied, while only small oscillations were found for five apexes of loops. The amplitudes of the oscillations were 0.4 − 5.7 % for intensity and 0.2 − 1.2 km s −1 for Doppler velocity. In addition, oscillations of only Doppler velocity were seen relatively less often in the data. We compared the amplitudes of intensity and those of Doppler velocity in order to identify MHD wave modes, and calculated the phase delays between Fourier components of intensity and those of Doppler velocity. The results are interpreted in terms of MHD waves as follows: (1) few kink modes or torsional Alfvén mode waves were seen in both moss regions and the apexes of loops; (2) upwardly propagating and standing slow mode waves were found in moss regions; and (3) consistent with previous studies, estimated values of energy flux of the waves were several orders of magnitude lower than that required for heating active regions.
We have studied the relationship between the velocity and temperature of a solar EUV jet. The highly accelerated jet occurred in the active region NOAA 10960 on 2007 June 5. Multi-wavelength spectral observations with EIS/Hinode allow us to investigate Doppler velocities at the wide temperature range. We analyzed the three-dimensional angle of the jet from the stereoscopic analysis with STEREO. Using this angle and Doppler velocity, we derived the true velocity of the jet. As a result, we found that the cool jet observed with He II 256Å log 10 T e [K] = 4.9 is accelerated to around 220km/s which is over the upper limit of the chromospheric evaporation. The velocities observed with the other lines are under the upper limit of the chromospheric evaporation while most of the velocities of hot lines are higher than that of cool lines. We interpret that the chromospheric evaporation and magnetic acceleration occur simultaneously. A morphological interpretation of this event based on the reconnection model is given by utilizing the multi-instrumental observations.
An infrared spectro-polarimeter installed on the Solar Flare Telescope at the Mitaka headquarters of the National Astronomical Observatory of Japan is described. The new spectro-polarimeter observes the full Sun via slit scans performed at two wavelength bands, one near 1565 nm for a Zeeman-sensitive spectral line of Fe i and the other near 1083 nm for He i and Si i lines. The full Stokes profiles are recorded; the Fe i and Si i lines give information on photospheric vector magnetic fields, and the helium line is suitable for deriving chromospheric magnetic fields. The infrared detector we are using is an InGaAs camera with 640 × 512 pixels and a read-out speed of 90 frames s−1. The solar disk is covered by two swaths (the northern and southern hemispheres) of 640 pixels each. The final magnetic maps are made of 1200 × 1200 pixels with a pixel size of $1{^{\prime\prime}_{.}}8$. We have been carrying out regular observations since 2010 April, and have provided full-disk, full-Stokes maps, at the rate of a few maps per day, on the internet.
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