6月9日（火）13：30～15：00 太陽系小天体セミナー Zoom
Jun 9 Tue Solar System Minor Body Seminar
6月10日（水）13：30～15：00 NAOJ Science Colloquium Zoom
Jun 10 Wed
6月12日（金）13：30～15：00 太陽天体プラズマセミナー Zoom
Jun 12 Fri Solar and Space Plasma Seminar
6月12日（金）16：00～17：00 談話会 Zoom
Jun 12 Fri NAOJ Seminar
詳細は以下をご覧下さい。
6月9日（火）
- キャンパス
- 三鷹
- セミナー名
- 太陽系小天体セミナー
- 定例・臨時の別
- 定例
- 日時
- 6月9日（火曜日）13時30分～15時
- 場所
- zoom
- 連絡先
- 名前：渡部潤一
- 備考
- テレビ会議またはスカイプによる参加も可
6月10日（水）
- Campus
- Mitaka
- Seminar
- NAOJ Science Colloquium
- Regularly Scheduled/Sporadic
- Wednesday
- Date and time
- 6/10 13:30-15:00
- Place
- Zoom
- Speaker
- Yudong Luo
- Affiliation
- University of Tokyo (student talk)
- Title
- A study of screening effect with Magnetic field
- Abstract
- In this talk, I will show some result of our exploration screening effects arising from a relativistic magnetized plasma with applications to different nuclear astrophysical site. The electron screening is the reduction of Coulomb potential on the electron cloud, since electrons and positrons will occupy certain Landau levels rather than the continuous momentum phase, the standard treatment of screening potential is not suitable within a background magnetic field. We investigated both the weak screening and strong screening correction on the electron capture rate. Taking into account the correction in Big Bang nucleosynthesis (BBN) arising from a homogeneous primordial magnetic field (PMF), we constrain the epoch at which the PMF was generated and its strength during BBN. Considering such screening corrections to the electron capture rates and using up-to-date observations of primordial elemental abundances. On the other hand, in the explosive nucleosynthesis site, i.e., MHD-Jet Supernovae. The nucleosynthesis in MHD-Jet SNe normally taken as independent from the magnetic field strength, but the reality is, for such high density plasma, electrons and positions are almost in the degenerate state, the Fermi energy highly depends on the magnetic field strength. Therefore, at high temperature region, where the nuclei statistical equilibrium still maintains, one can expect that the electron fraction Ye, which is determined by the electron capture reaction rate, also the key parameter to determine the final r-process nucleosynthesis yields, should be reconsidered.
- Facilitator
- -Name：Akimasa Kataoka
6月12日（金）
- Campus
- Mitaka
- Seminar
- Solar and Space Plasma Seminar
- Regularly Scheduled/Sporadic
- Regular
- Date and time
- 12 June (Fri), 13:30-15:00
- Place
- zoom
- Speaker
- Munehito Shoda
- Affiliation
- SSO/NAOJ
- Title
- overviewing scientific results from Parker Solar Probe
- Abstract
- Parker Solar Probe, a mission to “touch the Sun”, is currently undergoing its 5th encounter with perihelion < 30Rs from the center of the Sun. Although PSP is still much farer than its expected closest perihelion, it has already provided us several surprising results, including ubiquitous magnetic switchbacks, anomalously fast solar-wind rotation, clear evidence of prominence eruption, and the direct connection between SEP and its origin. In this talk, I will review the results from Parker Solar Probe, and some theoretical works related to PSP observations. I will also show my current simulation study that indicates in-situ generation of magnetic switchbacks, as opposed to conventional hypothesis that the switchbacks come from the reconnection events in the solar corona.
- Facilitator
- -Name：Munehito Shoda
6月12日（金）
- Campus
- Mitaka
- Seminar
- NAOJ Seminar (国立天文台談話会)
- Regularly Scheduled/Sporadic
- Sporadic?
- Date and time
- 6/12 (Fri) 16:00-17:00
- Place
- Zoom
- Speaker
- Prof. Hideko Nomura (野村英子)
- Affiliation
- Division of Science, NAOJ
- Title
- 原始惑星系円盤中の水と複雑な有機分子
- Abstract
- 惑星は、原始惑星系円盤中の塵とガスから形成される。
すばる光赤外線望遠鏡や大型電波干渉計ALMAなどによる近年の高空間分解能
観測により、円盤内の惑星形成領域の塵とガスの詳細構造が明らかになり、
惑星形成を示唆する構造も見つかってきた。
一方で、円盤からの分子輝線の観測により、円盤内の物質組成に関する
情報も得られるようになった。特にALMAは、円盤中の分子のスノーラインや
複雑な有機分子の観測を可能にした。また、これらの観測的進展とともに、
詳細な円盤の物理・化学構造モデルが構築されるようになり、それに基づき、
円盤内の物質進化が議論されている。本講演では、これらの観測や円盤モデルに
基づき、特に氷化学に着目して、原始惑星系円盤と彗星などの太陽系内物質を
つなぐ複雑な有機分子の進化を議論する。また、TMTやSPICAなどの次世代赤外線
望遠鏡による原始惑星系円盤内物質の観測の展望を紹介する - Facilitator
- -Name：Akimasa Kataoka