The search for the acceleration site in a solar flare

• Project/Area Number: 17K05397
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Astronomy
• Research Institution: National Astronomical Observatory of Japan
• Principal Investigator: SHIMOJO Masumi 国立天文台, アルマプロジェクト, 准教授 (00332164)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000); Fiscal Year 2019: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2018: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2017: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
• Keywords: 電波観測 / ミリ波 / ALMA / 太陽フレア / 彩層 / スピキュール / 太陽 / 電波 / CME / SEP / 電波干渉計 / 電波天文学 / 粒子加速 / 太陽物理学

Outline of Final Research Achievements

Solar radio observations with millimeter-wave can reveal not only the physical conditions of the chromosphere but also the behavior of high-energy electrons accelerated in a solar flare. However, solar millimeter-wave observations with a few arc-seconds spatial resolutions had not been done by the difficulties of realizing such observations.
We developed the observing scheme of the Sun with Atacama Large Millimeter/submillimeter Array (ALMA) that is the largest interferometer for observing celestial objects. We succeeded in observing a small solar flare and a spicule, which is a small jet in the chromosphere, with about 2 arc-second resolution using our scheme and deriving the physical parameters of these phenomena from the millimeter data for the first in the world.

Academic Significance and Societal Importance of the Research Achievements

ミリ波による高空間分解能での太陽電波観測を実現しただけでなく、ミリ波データによる太陽研究手法を開拓したことが、本研究成果の学術的意義である。ミリ波による太陽研究を今後活発化することにより、太陽の活動現象の理解が深化するだけでなく、現代に生きる我々が多用している地球近辺の宇宙環境の理解も一層深まると思われる。

Research Products

• [Int'l Joint Research] National Solar Observatory/Air Force Research Laboratory/New Jersey Institute of Technology(米国)
• [Int'l Joint Research] NRAO/AFRL/NJIT(米国)
• [Int'l Joint Research] University of Glasgow/Cavendish Laboratory(英国)
• [Int'l Joint Research] ESO(ドイツ)
• [Int'l Joint Research] Joint ALMA office(チリ)
• [Int'l Joint Research] KASI(韓国)
• [Int'l Joint Research]
• [Int'l Joint Research] National Radio Astronomy Observatory/Air Force Research Laboratory/New Jersey Institute of Technology(米国)
• [Int'l Joint Research] University of Glasgow/Cavendish Laboratory(英国)
• [Int'l Joint Research] European Southern Observatory/Max Planck Institute(ドイツ)
• [Int'l Joint Research] Joint ALMA Observatory(チリ)
• [Int'l Joint Research] Astronomical Institute(チェコ)
• [Int'l Joint Research]
• [Journal Article] Estimating the Temperature and Density of a Spicule from 100 GHz Data Obtained with ALMA (2020)
  • Author(s): Shimojo Masumi、Kawate Tomoko、Okamoto Takenori J.、Yokoyama Takaaki、Narukage Noriyuki、Sakao Taro、Iwai Kazumasa、Fleishman Gregory D.、Shibata Kazunari
  • Journal Title: The Astrophysical Journal Volume: 888 Issue: 2 Pages: L28-L28
  • DOI: 10.3847/2041-8213/ab62a5
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The Disappearing Solar Filament of 2013 September 29 and Its Large Associated Proton Event: Implications for Particle Acceleration at the Sun (2019)
  • Author(s): Cliver E. W.、Kahler S. W.、Kazachenko M.、Shimojo M.
  • Journal Title: The Astrophysical Journal Volume: 877 Issue: 1 Pages: 11-11
  • DOI: 10.3847/1538-4357/ab0e03
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Observations of photospheric magnetic structure below a dark filament using the Hinode Spectro-Polarimeter (2019)
  • Author(s): Yokoyama Takaaki、Katsukawa Yukio、Shimojo Masumi
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 71 Issue: 2 Pages: 46-46
  • DOI: 10.1093/pasj/psz014
  • Peer Reviewed
• [Journal Article] Achievements of Hinode in the first eleven years (2019)
  • Author(s): Hinode Review Team、including Shimizu Toshifumi
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 71 Issue: 5
  • DOI: 10.1093/pasj/psz084
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] First analysis of solar structures in 1.21 mm full-disc ALMA image of the Sun (2018)
  • Author(s): Brajsa R.、Sudar D.、Benz A. O.、Skokic I.、Barta M.、De Pontieu B.、Kim S.、Kobelski A.、Kuhar M.、Shimojo M.、Wedemeyer S.、White S.、Yagoubov P.、Yan Y.
  • Journal Title: Astronomy & Astrophysics Volume: 613 Pages: A17-A17
  • DOI: 10.1051/0004-6361/201730656
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] ALMA Observations of the Solar Chromosphere on the Polar Limb (2018)
  • Author(s): Yokoyama Takaaki、Shimojo Masumi、Okamoto Takenori J.、Iijima Haruhisa
  • Journal Title: The Astrophysical Journal Volume: 863 Issue: 1 Pages: 96-96
  • DOI: 10.3847/1538-4357/aad27e
  • Peer Reviewed
• [Journal Article] Exploring the Sun with ALMA (2018)
  • Author(s): Bastian, T. S., Barta, M, Braja, R., Chen, B., Pontieu, B. D., Gary, D. E., Fleishman, G. D., Hales, A. S., Iwai, K., Hudson, H., Kim, S., Kobelski, A., Loukitcheva, M., Shimojo, M., Skokia, I,; Wedemeyer, S., White, S. M., Yan, Y.
  • Journal Title: The Messenger Volume: 171 Pages: 25-30
  • Open Access / Int'l Joint Research
• [Journal Article] The First ALMA Observation of a Solar Plasmoid Ejection from an X-Ray Bright Point (2017)
  • Author(s): Shimojo Masumi、Hudson Hugh S.、White Stephen M.、Bastian Timothy S.、Iwai Kazumasa
  • Journal Title: Astrophysical Journal Letter Volume: 841 Issue: 1 Pages: L5-L5
  • DOI: 10.3847/2041-8213/aa70e3
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] ALMA Discovery of Solar Umbral Brightness Enhancement at λ = 3 mm (2017)
  • Author(s): Iwai Kazumasa、Loukitcheva Maria、Shimojo Masumi、Solanki Sami K.、White Stephen M.
  • Journal Title: Astrophysical Journal Letter Volume: 841 Issue: 2 Pages: L20-L20
  • DOI: 10.3847/2041-8213/aa71b5
  • NAID: 120006343669
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Observing the Sun with the Atacama Large Millimeter/submillimeter Array (ALMA): High-Resolution Interferometric Imaging (2017)
  • Author(s): Shimojo M.、Bastian T. S.、Hales A. S.、White S. M.、Iwai K.、Hills R. E.、Hirota A.、Phillips N. M.、Sawada T.、Yagoubov P.、Siringo G.、Asayama S.、Sugimoto M.、Brajsa R.、Skokic I.、Barta M.、Kim S.、de Gregorio-Monsalvo I.、Corder S. A.、et al.
  • Journal Title: Solar Physics Volume: 292 Issue: 7 Pages: 87-87
  • DOI: 10.1007/s11207-017-1095-2
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Observing the Sun with the Atacama Large Millimeter/submillimeter Array (ALMA): Fast-Scan Single-Dish Mapping (2017)
  • Author(s): White S. M.、Iwai K.、Phillips N. M.、Hills R. E.、Hirota A.、Yagoubov P.、Siringo G.、Shimojo M.、Bastian T. S.、Hales A. S.、Sawada T.、Asayama S.、Sugimoto M.、Marson R. G.、Kawasaki W.、Muller E.、Nakazato T.、Sugimoto K.、et al.
  • Journal Title: Solar Physics Volume: 292 Issue: 7 Pages: 88-88
  • DOI: 10.1007/s11207-017-1123-2
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] A First Comparison of Millimeter Continuum and Mg ii Ultraviolet Line Emission from the Solar Chromosphere (2017)
  • Author(s): Bastian T. S.、Chintzoglou G.、De Pontieu B.、Shimojo M.、Schmit D.、Leenaarts J.、Loukitcheva M.
  • Journal Title: Astrophysical Journal Letter Volume: 845 Issue: 2 Pages: L19-L19
  • DOI: 10.3847/2041-8213/aa844c
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Variation of the Solar Microwave Spectrum in the Last Half Century (2017)
  • Author(s): Shimojo Masumi、Iwai Kazumasa、Asai Ayumi、Nozawa Satoshi、Minamidani Tetsuhiro、Saito Masao
  • Journal Title: The Astrophysical Journal Volume: 848 Issue: 1 Pages: 62-62
  • DOI: 10.3847/1538-4357/aa8c75
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Solar ALMA Observations: Constraining the Chromosphere above Sunspots (2017)
  • Author(s): Loukitcheva Maria A.、Iwai Kazumasa、Solanki Sami K.、White Stephen M.、Shimojo Masumi
  • Journal Title: Astrophysical Journal Volume: 850 Issue: 1 Pages: 35-35
  • DOI: 10.3847/1538-4357/aa91cc
  • Peer Reviewed / Int'l Joint Research
• [Presentation] Multi-thermal structures in a spicule observed with ALMA, IRIS, and AIA/SDO (2019)
  • Author(s): Masumi Shimojo, Tomoko Kawate, Takenori Okamoto, Takaaki Yokoyama
  • Organizer: 日本地球惑星科学連合2019年大会
• [Presentation] ALMA によるスピキュール物理量の導出 (2019)
  • Author(s): 下条圭美, 川手朋子, 岡本丈典, 横山央明
  • Organizer: 日本天文学会2019年秋季年会
• [Presentation] Cold and hot spicules observed with ALMA, IRIS and AIA/SDO (2019)
  • Author(s): Masumi Shimojo, Tomoko Kawate, Takenori Okamoto, Takaaki Yokoyama
  • Organizer: Hinode13/IPELS2019
  • Int'l Joint Research
• [Presentation] Estimating the temperature and density of a spicule from 100 GHz data obtained with ALMA (2019)
  • Author(s): Shimojo, M.; Kawate, T.; Okamoto, T. J.; Yokoyama, T.
  • Organizer: American Geophysical Union, Fall Meeting 2019
  • Int'l Joint Research
• [Presentation] Solar Science with ALMA (2018)
  • Author(s): Shimojo, M.
  • Organizer: XXXth General Assembly of the International Astronomical Union
  • Int'l Joint Research / Invited
• [Presentation] Initial Results from ALMA solar observations (2018)
  • Author(s): Shimojo, M. and
  • Organizer: Hinode-12: The Many Suns
  • Int'l Joint Research / Invited
• [Presentation] 太陽大気におけるミリ波帯水素再結合線の探索 (2018)
  • Author(s): 下条圭美
  • Organizer: 日本天文学会秋季年会
• [Presentation] New Window of Solar Physics: Solar Observations with ALMA (2017)
  • Author(s): Shimojo Masumi and ALMA Solar development team
  • Organizer: JOINT HINODE-11/IRIS-8 SCIENCE MEETING
  • Int'l Joint Research / Invited
• [Presentation] The first ALMA observation of a plasmoid ejection from an X-ray bright point (2017)
  • Author(s): Shimojo Masumi, Hudson Hugh S.、White Stephen M.、Bastian Timothy S.、Iwai Kazumasa
  • Organizer: 32nd URSI General Assembly & Science Symposium
  • Int'l Joint Research / Invited
• [Presentation] The first ALMA observation of a plasmoid ejection from an X-ray bright point (2017)
  • Author(s): Shimojo Masumi, Hudson Hugh S.、White Stephen M.、Bastian Timothy S.、Iwai Kazumasa
  • Organizer: 4th Asia-Pacific Solar Physics Meeting
  • Int'l Joint Research
• [Presentation] The first ALMA observation of a plasmoid ejection from an X-ray bright point (2017)
  • Author(s): Shimojo Masumi, Hudson Hugh S.、White Stephen M.、Bastian Timothy S.、Iwai Kazumasa
  • Organizer: American Geophysical Union, Fall Meeting 2017
  • Int'l Joint Research
• [Presentation] ALMAによるプラズモイド放出現象の観測 (2017)
  • Author(s): 下条圭美、Hudson Hugh S.、White Stephen M.、Bastian Timothy S.、岩井一正
  • Organizer: 日本天文学会秋季年会
• [Remarks] ALMA-Sol-CDAW19
  • URL: https://hinode.nao.ac.jp/user/shimojo/ALMA_WS_Solar_HP/Tokyo_2019.html