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Kwangsu Ahn Jongchul Chae Kyung-Suk Cho Donguk Song Heesu Yang Philip R. Goode Wenda Cao Hyungmin Park Jakyung Nah Bi-Ho Jang Young-Deuk Park 《Solar physics》2014,289(11):4117-4136
The Fast Imaging Solar Spectrograph (FISS) is being operated on the New Solar Telescope of the Big Bear Solar Observatory. It simultaneously records spectra of Hα and Ca ii 8542 Å lines, and this dual-spectra measurement provides an estimate of the temperature and nonthermal speed components. We observed a loop structure in AR 11305 using the FISS, SDO/AIA, and STEREO/EUVI in 304 Å, and found plasma material falling along the loop from a coronal height into the umbra of a sunspot, which accelerated up to 80 km?s?1. We also observed C2 and C7 flare events near the loop. The temperature of the downflows was in the range of 10?000?–?33?000 K, increasing toward the umbra. The temperature of the flow varied with time, and the temperature near the footpoint rose immediately after the C7 flare, but the temperature toward the umbra remained the same. There seemed to be a temporal correlation between the amount of downflow material and the observed C-class flares. The downflows decreased gradually soon after the flares and then increased after a few hours. These high-speed red-shift events occurred continuously during the observations. The flows observed on-disk in Hα and Ca ii 8542 Å appeared as fragmented, fuzzy condensed material falling from the coronal heights when seen off-limb with STEREO/EUVI at 304 Å. Based on these observations, we propose that these flows were an on-disk signature of coronal rain. 相似文献
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Jongchul Chae Hyung-Min Park Kwangsu Ahn Heesu Yang Young-Deuk Park Jakyoung Nah Bi Ho Jang Kyung-Suk Cho Wenda Cao Philip R. Goode 《Solar physics》2013,288(1):1-22
For high resolution spectral observations of the Sun – particularly its chromosphere, we have developed a dual-band echelle spectrograph named Fast Imaging Solar Spectrograph (FISS), and installed it in a vertical optical table in the Coudé Lab of the 1.6 meter New Solar Telescope at Big Bear Solar Observatory. This instrument can cover any part of the visible and near-infrared spectrum, but it usually records the Hα band and the Ca ii 8542 Å band simultaneously using two CCD cameras, producing data well suited for the study of the structure and dynamics of the chromosphere and filaments/prominences. The instrument does imaging of high quality using a fast scan of the slit across the field of view with the aid of adaptive optics. We describe its design, specifics, and performance as well as data processing 相似文献
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Hyungmin Park Jongchul Chae Donguk Song Ram Ajor Maurya Heesu Yang Young-Deuk Park Bi-Ho Jang Jakyoung Nah Kyung-Suk Cho Yeon-Han Kim Kwangsu Ahn Wenda Cao Philip R. Goode 《Solar physics》2013,288(1):105-116
We observed solar prominences with the Fast Imaging Solar Spectrograph (FISS) at the Big Bear Solar Observatory on 30 June 2010 and 15 August 2011. To determine the temperature of the prominence material, we applied a nonlinear least-squares fitting of the radiative transfer model. From the Doppler broadening of the Hα and Ca ii lines, we determined the temperature and nonthermal velocity separately. The ranges of temperature and nonthermal velocity were 4000?–?20?000 K and 4?–?11 km?s?1. We also found that the temperature varied much from point to point within one prominence. 相似文献
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RIPPLES OF HOPE: ACEHNESE REFUGEES IN POST-TSUNAMI MALAYSIA 总被引：1，自引：0，他引：1
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