4月11日（火）13：30～15：00 太陽系小天体セミナー 南棟２階会議室
Apr 11 tue Solar System Minor Body Seminar Conference Room, South Bldg.2F
4月12日（水）13：30～14：30 理論コロキウム コスモス会館会議室
Apr 12 wed DTA colloquium Conference Room, Cosmos Lodge
4月14日（金）13：30～15：00 太陽天体プラズマセミナー 院生セミナー室
Apr 14 fri Solar and Space Plasma Seminar Student Seminar Room, Subaru Bldg.
4月14日（金）16：00～17：00 国立天文台談話会 大セミナー室
Apr 14 fri NAOJ Seminar Large Seminar Room
詳細は以下をご覧下さい。
4月11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
- 4月11日（火曜日）13時30分～15時
- 場所
- 南棟２階会議室
- 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
4月12日（水）
- Campus
- Mitaka
- Seminar
- DTA colloquium
- Regularly Scheduled/Sporadic
- Regularly Scheduled
- Date and time
- 12 April 2017, 13:30-14:30
- Place
- Conference Room, Cosmos Lodge
- Speaker
- Shing Chi Leung
- Affiliation
- Kavli IPMU, U. Tokyo
- Title
- Nucleosynthesis of Type Ia supernovae
- Abstract
- Type Ia supernovae (SNe Ia) are an important class of astrophysical objects. They are the standard candles of the universe and the major sources of iron-peak elements. It is known to be the explosion of a carbon-oxygen white dwarf by thermonuclear runaways. However, many theoretical uncertainties still persist, for example whether the progenitor of SNe Ia belongs to single degenerate or double degenerate scenario. Furthermore, the diversity in observations, such as the subclasses of Type Iax or super-luminous SNe Ia, suggests that the standard picture using the explosion of a Chandrasekhar mass white dwarf is insufficient to explain the variety of the observed SNe Ia. To resolve these, a systematic understanding in SNe Ia nucleosynthesis becomes necessary. In this present, I shall present hydrodynamics and nucleosynthesis results of multi-dimensional models for the explosion phase of SNe Ia. We explore the effects of model parameters on the explosion energetic and its chemical production. The influences of our SNe Ia models to galactic chemical evolution are discussed. I also present constraints on the progenitor properties of some recently observed SNe Ia and their remnants.
- Facilitator
- -Name：Tomoya Takiwaki
- Comment
- in English
4月14日（金）
- Campus
- Mitaka
- Seminar
- Solar and Space Plasma Seminar
- Regularly Scheduled/Sporadic
- Regular
- Date and time
- 14 April (Fri), 13:30-15:00
- Place
- Student Seminar Room, Subaru Bldg.
- Speaker
- Tomoko Kawate
- Affiliation
- ISAS/JAXA
- Title
- Temporal Evolution and Spatial Distribution of White-light Flare Kernels in a Solar Flare
- Abstract
-
WL sources in solar flares mainly appear in the impulsive phase of energetic flares, and have good temporal and spatial correlations with hard X-ray emission. However, transporting energy via nonthermal electrons into the photosphere where continuum emission originates in the standard solar atmosphere is difficult. Therefore, the emission mechanisms and the source regions of WL flares are still being debated On 2011 September 6, we observed an X2.1-class flare in continuum and Hα with a frame rate of about 30 Hz. After processing images of the event by using a speckle-masking image reconstruction, we identified white-light (WL) flare ribbons on opposite sides of the magnetic neutral line. We derive the light curve decay times of the WL flare kernels at each resolution element by assuming that the kernels consist of one or two components that decay exponentially, starting from the peak time. As a result, 42% of the pixels have two decay-time components with average decay times of 15.6 and 587 s, whereas the average decay time is 254 s for WL kernels with only one decay-time component. The peak intensities of the shorter decay-time component exhibit good spatial correlation with the WL intensity, whereas the peak intensities of the long decay-time components tend to be larger in the early phase of the flare at the inner part of the flare ribbons, close to the magnetic neutral line. The average intensity of the longer decay-time components is 1.78 times higher than that of the shorter decay-time components.
If the shorter decay time is determined by either the chromospheric cooling time or the nonthermal ionization timescale and the longer decay time is attributed to the coronal cooling time, this result suggests that WL sources from both regions appear in 42% of the WL kernels and that WL emission of the coronal origin is sometimes stronger than that of chromospheric origin. - Facilitator
- -Name：Shin Toriumi
- Comment
4月14日（金）
- キャンパス
- 三鷹
- セミナー名
- 国立天文台談話会
- 定例・臨時の別
- 定例
- 日時
- 4月14日（金） 16:00-17:00
- 場所
- 大セミナー室
- 講演者
- Colin Norman
- 所属
- Johns Hopkins University
- タイトル
- THE FORMATION, EVOLUTION AND ENVIRONMENTS OF RADIO GALAXIES AND ACTIVE GALAXIES
- Abstract
- Active galaxies host in their centers supermassive black holes which have powerful luminosities via processes associated with accretion. The impact of these powerful nuclear engines on the evolution of galaxies and structure on super-galactic scales is one of the major open questions in astrophysics. The formation and evolution of active galaxies and radio galaxies will be examined at both high and low redshift with particular emphasis on the immediate environment of galaxies and clusters. The underlying physics of multi-phase media in these extreme conditions will be analyzed. The significant relationship between starbursts and activity will be discussed.
- 連絡先
- -名前：久保 雅仁
以上