Abstract: The explosive death of massive stars starts with the collapse of their coreand the formation of a neutron star. Understanding the reversal of the collapse into an explosion is still a challenge despite decades of theoretical efforts.The breaking of spherical symmetry is triggered by the development of hydrodynamical instabilities, which affect the kick and spin of the neutron star and favour an asymmetric explosion. Neutrino driven convection and the Standing Accretion Shock Instability (SASI) are the dominant instabilities,depending on the structure of the progenitor. I will characterize the properties and consequences of these instabilities using simplified numerical simulations, and a shallow water experiment named SWASI. The first results from a new version of the SWASI experiment illustrate the dynamical effects of rotation in the collapsing core.
Title: Mass distribution of first stars
Speaker: Wako Aoki (National Astronomical Observatory of Japan)
Time: Friday,3:30pm, Nov 28th
Location: the middle conference room
Abstract: Large surveys of metal-poor stars and follow-up high resolution spectroscopy have been revealing the chemical composition of low-mass halo stars that could record the nucleosynthesis of massive first-generation stars. This provides a unique constraint on the mass estimates of first stars, which is a key to understanding of the structure formation and enrichment of the early universe. I'll review the progress of observational studies of halo stars in the past decade, and show our recent result suggesting existence of very-massive stars among first stars.
Group meetings and additional talks
Observational High Energy Astrophysics Group Seminar
Location: 1401; Contact: Zhen Yan <zyan@shao.ac.cn>
Title: The Broadband XMM-Newton and NuSTAR X-ray Spectra of Two Ultraluminous X-ray Sources in the Galaxy IC 342 (Wengda Zhang)
The power of relativistic jets is larger than the luminosity of their accretion disks (Hui Zhang)
Supergiant fast X-ray transients as an under-luminous class of supergiant X-ray binaries (Holger Stiele)
Time: Monday, 10:30am, Nov 24
Stellar Cluster and Galaxy Seminar group seminar
Location: 1617; Contact: Jianling Gan <jlgan@shao.ac.cn>
Title: The galaxy pairs
Speaker: Shiyin Shen
Time: Wednesday, 10:30pm, Nov 26
AGN structure and evolution group Seminar
Location: 1617; Contact: Liang Chen<chenliang@shao.ac.cn>
Title: The power of relativistic jets is larger than the luminosity of their accretion disks
Ref. http://adsabs.harvard.edu/abs/2014arXiv1411.5368G
Speaker: Minfeng Gu
Time: Thursday, 10:00am, Nov 27
Blackhole accretion and High-energy astrophysics Seminar
Location: 1608; Contact: Qixiang Yang <qxyang@shao.ac.cn>
Title: Colours of black holes: infrared flares from the hot accretion disc in XTE J1550-564
Speaker: Fuguo Xie
Time: Tuesday, 2:00 pm, Nov 25
Title: Special Topics II: Gas in the Galactic Halo
Speaker: Guobin Mou
Time: Friday, 9:30 am, Nov 28
