::: 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 (2019)

    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: 2019-01-21 Mon 12:15~13:15 [R1203]
Speaker:Tzu-Hsiang Chao/Chia-Hui Lin
Topic:Cosmological Impacts of the First Stars/Kilonova and Binary Neutron Star Merger
download PDF: 下載 PDF
No. 時間地點 講者 題目(摘要)
12019-03-25 Mon
12:15~13:15
R1203
Miikka Väisälä
[ASIAA]
22019-03-04 Mon
12:15~13:15
R1203
Shutaro Ueda
[ASIAA]
32019-02-25 Mon
12:15~13:15
R1203
Po-Sheng Ou
[NTU/ASIAA]
Modeling the Mass loss of Massive Stars with MESA
42019-02-18 Mon
12:15~13:15
R1203
Li-Hsin Chen
[NTU/ASIAA]
Simulations of the First Galaxies
52019-02-11 Mon
12:15~13:15
R1203
Yen-Chen Pan
[EACOA Fellow, NAOJ]
Host galaxies of Ia SNe
62019-01-28 Mon
14:20~15:20
R1203
Katharina Wollenberg
[ITA, Heidelberg]
The Fragmentation Behavior of Population~III Protostellar Disks under the Influence of Turbulence and Rotation
Abstract

In cosmological simulations, it is found that the degree of fragmentation of the Population III (Pop III) protostellar disk varies strongly from halo to halo. This is to be expected if turbulence within the cloud plays a role in determining when and where fragmentation actually occurs. It is also reasonable to expect that the amount of angular momentum present at small-scales will have a large impact on Population III protostellar disk formation and evolution. We conducted a numerical study with the Voronoi moving-mesh AREPO in which we examined how different levels of initial subsonic turbulence and rotation within the star-forming cloud affect the outcome of Pop III star formation in terms of the total number of objects formed, the overall mass spectrum and the individual accretion history. We used controlled initial conditions which examine the collapse of a gas cloud with pre-defined levels of turbulence or rotation within a small computational box. This allowed us to draw conclusions on the specific role, strength and importance of the particular physical parameters applied here. In this talk, I will present some of our results and discuss the relevance of our numerical approach in which we have performed several realizations per combination of initial conditions and have averaged over the realizations instead of just considering single, individual runs.

72019-01-21 Mon
12:15~13:15
R1203
Tzu-Hsiang Chao/Chia-Hui Lin
[NTU/ASIAA]
Cosmological Impacts of the First Stars/Kilonova and Binary Neutron Star Merger
82019-01-14 Mon
12:15~13:15
R1203
Sung-Han Tsai
[ASIAA/NCU]
Binary Stellar Evolution Models with MESA
92019-01-07 Mon
12:15~13:15
R1203
Tiara Hung/Edward Ashton
[UCSC/UBC]
Searching for Tidal Disruption Events in the Optical Time Domain (Hung) / Searching the OSSOS dataset for unusual objects: slow movers and interlopers (Ashton)
Abstract

Hung<br> Ashton: This talk combines two projects that uses the Outer Solar System Origins Survey (OSSOS) dataset to search for unusual small bodies. The first search looked for objects beyond 300 au using an uncommon search technique, we use an algorithm to identify objects that appear stationary on the timescale of hours but not present days/weeks/months before and after. After visually scanning all the candidates no slow moving objects were discovered. From the null detection and using a survey simulator, we obtain a model-dependent 95% upper limit of 1000 on the number of `planetary objects', with absolute magnitudes in the range -3 < H < 2, in the distant Solar System. In the second search we looked for interstellar objects (IS0s) using a slightly altered version of the TNO detection software used by OSSOS. No ISOs were discovered. However, we have found bound objects traveling at motions (when observed only over short arcs) that an ISO in the outer Solar System could have, and we show how previous moving-object surveys may have detected ISOs but incorrectly assigned them to bound orbits.

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