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ALMA Discovery of Solar Umbral Brightness Enhancement at λ=3mm
http://hdl.handle.net/2237/26956
http://hdl.handle.net/2237/26956ddd3668c-538f-4353-8897-8a67a9ee6257
| 名前 / ファイル | ライセンス | アクション |
|---|---|---|
Iwai_2017_ApJL_841_L20.pdf (3.6 MB)
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| アイテムタイプ | 学術雑誌論文 / Journal Article(1) | |||||
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| 公開日 | 2017-09-05 | |||||
| タイトル | ||||||
| タイトル | ALMA Discovery of Solar Umbral Brightness Enhancement at λ=3mm | |||||
| 言語 | en | |||||
| 著者 |
Iwai, Kazumasa
× Iwai, Kazumasa× Loukitcheva, Maria× Shimojo, Masumi× Solanki, Sami K.× White, Stephen M. |
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| アクセス権 | ||||||
| アクセス権 | open access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_abf2 | |||||
| 権利 | ||||||
| 権利情報 | © 2017. The American Astronomical Society | |||||
| 言語 | en | |||||
| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | We report the discovery of a brightness enhancement in the center of a large sunspot umbra at a wavelength of 3 mm using the Atacama Large Millimeter/sub-millimeter Array (ALMA). Sunspots are among the most prominent features on the solar surface, but many of their aspects are surprisingly poorly understood. We analyzed a λ = 3 mm (100 GHz) mosaic image obtained by ALMA that includes a large sunspot within the active region AR12470, on 2015 December 16. The 3 mm map has a 300'' × 300'' field of view and 4farcs9 × 2farcs2 spatial resolution, which is the highest spatial resolution map of an entire sunspot in this frequency range. We find a gradient of 3 mm brightness from a high value in the outer penumbra to a low value in the inner penumbra/outer umbra. Within the inner umbra, there is a marked increase in 3 mm brightness temperature, which we call an umbral brightness enhancement. This enhanced emission corresponds to a temperature excess of 800 K relative to the surrounding inner penumbral region and coincides with excess brightness in the 1330 and 1400 Å slit-jaw images of the Interface Region Imaging Spectrograph (IRIS), adjacent to a partial lightbridge. This λ = 3 mm brightness enhancement may be an intrinsic feature of the sunspot umbra at chromospheric heights, such as a manifestation of umbral flashes, or it could be related to a coronal plume, since the brightness enhancement was coincident with the footpoint of a coronal loop observed at 171 Å. | |||||
| 言語 | en | |||||
| 出版者 | ||||||
| 出版者 | IOP publishing | |||||
| 言語 | en | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプresource | http://purl.org/coar/resource_type/c_6501 | |||||
| タイプ | journal article | |||||
| 出版タイプ | ||||||
| 出版タイプ | VoR | |||||
| 出版タイプResource | http://purl.org/coar/version/c_970fb48d4fbd8a85 | |||||
| DOI | ||||||
| 関連タイプ | isVersionOf | |||||
| 識別子タイプ | DOI | |||||
| 関連識別子 | https://doi.org/10.3847/2041-8213/aa71b5 | |||||
| ISSN | ||||||
| 収録物識別子タイプ | PISSN | |||||
| 収録物識別子 | 2041-8205 | |||||
| 書誌情報 |
en : The Astrophysical Journal Letters 巻 841, 号 2, p. L20-L20, 発行日 2017-06-01 |
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| 著者版フラグ | ||||||
| 値 | publisher | |||||
| URI | ||||||
| 識別子 | https://doi.org/10.3847/2041-8213/aa71b5 | |||||
| 識別子タイプ | DOI | |||||
| URI | ||||||
| 識別子 | http://hdl.handle.net/2237/26956 | |||||
| 識別子タイプ | HDL | |||||
