::: 網站導覽 English VersionEnglish 列印友善列印 搜尋說明
學術活動 > 午餐會報

午餐會報 (2017)

    連絡窗口
  • 午餐會報: 研討會委員(talks_replace2@_asiaa.sinica.edu.tw)
  • 實驗室午餐會報: 黃彥儒 (yenruhuang_replace2@_asiaa.sinica.edu.tw)
近期午餐會報: 2017-06-12 Mon 12:00~13:00 [R1203]
Speaker:Yusuke Aso
download PDF: 下載 PDF
No. 時間地點 講者 題目(摘要)
12017-07-24 Mon
12:00~13:00
R1203
Shohei Aoyama
[ASIAA]
22017-07-17 Mon
12:00~13:00
R1203
Shoko Koyama
[ASIAA]
32017-07-10 Mon
12:00~13:00
R1203
Alfonso Trejo-Cruz
[ASIAA]
ALMA ARC activity
42017-07-03 Mon
12:00~13:00
R1203
no lunch talk
[ASIAA]
APRIM
52017-06-26 Mon
12:00~13:00
R1203
Ui-Han Zhang
[NTU]
Magnetohydrodynamics with GAMER: HybridMPI/OpenMP GPU parallelization in AMR
Abstract

GAMER, a parallel graphic-processing-unit-accerelated adaptive-mesh-refinement hydrodynamic code, has been extended to support magnetohydrodynamics (MHD). The algorithm for MHD is the corner-transport-upwind (CTU) scheme with the constraint transport (CT) technique. The divergent preserving operator for adaptive mesh refinement (AMR) is applied to enforce the divergence-free constraint on the magnetic field. The overall performance banchmarks are conducted to AMD Opteron Processer 6276 (16 processing cores) CPU with Tesla K20X GPU. The uniform grid comparison between GAMER and Athena++, a well-known and widely used pubic code for Astrophysics, is made. It shows that under the same accuracy, GAMER with one GPU is able to achieve about 1/30 computation time of Athena++ with Haswell Xeon E5- 2690v3 which is a 24-processing-cores CPU. Our AMR tests demonstrate that the GAMER’s performance is robust and as good as with the uniform grid case. Furthermore, with the hybrid the message passing interface (MPI)/Open Multi-Processing (OpenMP) parallelization, the computation performance is capable of full exploitation of a heterogeneous CPU/GPU cluster with no latency. Finally, a new stability test problem of a uniform plasma with Arnold-Beltrami-Childress flow (ABC-flow) pattern for the magnetic field is demonstrated for the overall performance examining and it gives some interesting results. Roughly speaking, the system with the longest wave length of the magnetic field is linearly stable and the second longest one is unstable. Furthermore, the unstable one will cast to another stable configuration in which only the largest scale structure appears.

62017-06-19 Mon
12:00~13:00
R1203
Lapo Fanciullo
[ASIAA]
72017-06-12 Mon
12:00~13:00
R1203
Yusuke Aso
[ASIAA]
82017-05-24 Wed
12:00~13:00
R1203
Yang, Ping-Hsueh
[ASIAA]
TBD
92017-05-15 Mon
12:00~13:00
R1203
Kuan-Chou Hou
[ASIAA]
Dust enrichment in galaxy and cosmology simulations
102017-05-10 Wed
12:00~13:00
R1203
Yen, Sheng-Feng
[ASIAA]
wSMA series: My Baker Life - The LDPE Anti-reflection Coating
Abstract

In this talk, I will mention why we need and quartz windows. And why using LDPE to reduce the reflection. How we coated the LDPE ( Low-density polyethylene ) at the quartz surface. And preliminary result.

112017-05-08 Mon
12:00~13:00
R1203
Satoki Matsushita
[ASIAA]
Working in Greenland in the Middle of Winter
122017-04-26 Wed
12:00~13:00
R1203
Chang, Yin-Chang
[ASIAA]
The TAOS 2 Camera Dewar Assembly
132017-04-24 Mon
12:00~13:00
R1203
Kota Naito
[ASIAA/NTU]
Statistical Study on Organic Inclusions in Meteorites
142017-04-17 Mon
12:00~13:00
R1203
Min-Kai Lin
[ASIAA]
Dusty disk-planet simulations
Abstract

I will present ongoing simulations to study the interaction between protoplanetary disks and embedded protoplanets using a modified version of the PLUTO code. I will show how dusty disk-planet torques can differ from that in pure gas disks, which is considered in most previous studies.

152017-04-12 Wed
12:00~13:00
R1203
Chiang, Po-Han
[ASIAA]
162017-03-29 Wed
12:00~13:00
R1203
Chiu, Chuang Ping
[ASIAA]
1.5THz Cartridge System
172017-03-27 Mon
12:00~13:00
R1203
Peter Scicluna
[ASIAA]
Observing mass-loss from evolved massive stars
182017-03-15 Wed
12:00~13:00
R1203
Chueh-Yi Chou
[ASIAA]
PFS fiber probe calibration unit
192017-03-01 Wed
12:00~13:00
R1203
Yen-Bin Chang
[ASIAA]
Fabrication of orthomode transducer for wSMA
202017-02-20 Mon
12:00~13:00
R1203
Kouichi Hirotani
[ASIAA]
Emission from the direct vicinity of black holes
Abstract

In a black hole magnetosphere, when the plasma accretion rate is much lower than the Eddington limit, a strong electric field inevitably appears along the magnetic field lines due to charge deficit. In such a charge-starved region (or a gap), the electric field accelerates migratory electrons and positrons into ultra relativistic energies. These relativistic leptons emit copious gamma-rays via curvature and inverse-Compton (IC) processes. Some of such gamma-rays collide with the submillimeter-IR photons emitted from the radiatively inefficient accretion flow (RIAF) to materialize as pairs. The created pairs polarize to partially screen the original acceleration electric field. By solving this pair-creation cascade self-consistently for the first time, we find that the gap emissions from the direct vicinity of stellar-mass, intermediate-mass, and super-massive black holes are detectable with Fermi/LAT and Imaging Atmospheric Cherenkov Telescopes (e.g., MAGIC, HESS, VERITAS, and CTA) when the accretion rate is in a certain range. Moreover, such HE/VHE gamma-ray fluxes are predicted to exhibit anti-correlation with the RIAF submillimeter fluxes, which enables us to discriminate the gap emission from the standard, shock-in-jet model, e.g., by using ALMA and CTA.

212017-02-15 Wed
12:00~13:00
R1203
Li Chao-Te
[ASIAA]
Millimeter Wave Grating Spectrometer for TIME
222017-02-13 Mon
12:00~13:00
R1203
Youichi Ohyama
[ASIAA]
Proposing to Subaru
232017-02-06 Mon
12:00~13:00
R1203
Ai-Lei Sun
[ASIAA]
Characterizing AGN [OIII] Extended Emission Line Regions with SDSS Images.
242017-01-18 Wed
12:00~13:00
R1203
Chen, Chung-Cheng
[ASIAA]
When Something is Broken...
252017-01-09 Mon
12:00~13:00
R1203
Shiang-Yu Wang
[ASIAA]
the Chinese large optical telescope projects
262017-01-04 Wed
12:00~13:00
R1203
Ling Hung-Hsu
[ASIAA]
Detector quality assurance for astronomy instrumentation
電話: 886-2-3365-2200 傳真: 886-2-2367-7849
一般事務: asiaa_replace2@_asiaa.sinica.edu.tw 媒體連絡: epo_replace2@_asiaa.sinica.edu.tw
台北市10617羅斯福路四段1號 中央研究院/台灣大學天文數學館11樓