网站yabo88vip登陆  > 学术活动  > 学术报告
Cosmic-ray acceleration by supernova remnant shocks and the peculiar case of Cas A’s reverse shock
报告题目:Cosmic-ray acceleration by supernova remnant shocks and the peculiar case of Cas A’s reverse shock
报 告  人:Dr. Jacco Vink (University of Amsterdam)
报告时间:2021-11-25 16:00:00

Abstract: I will provide an overview of our current knowledge of supernova remnant (SNR) evolution and in particular cosmic-ray acceleration by young SNRs. Young SNRs have faster shocks, and show evidence for X-ray synchrotron emission, requiring highly turbulence magnetic field, and there is now also ample evidence that the magnetic fields near their shocks have been amplified. An important, but also peculiar, case is the 330 yr old SNR Cassiopeia A. Its magnetic-field near the shock is ~200 muG, but not only the forward shock shows X-ray synchrotron emission, also part of its reverse shock. I will conclude with a new study of the dynamics of both the forward and reverse shock using proper motion measurements based on 19 year of Chandra X-ray observations, and I will discuss the implications for cosmic-ray acceleration.

Bio: Jacco Vink is an associate professor at the Anton Pannekoek Institute and GRAPPA at the University of Amsterdam, and also affiliated with SRON Netherlands Institute of Space Research.  He is among the leading experts of supernova remnants. His current research focusses on the question of how efficiently cosmic rays are accelerated by supernova remnant shocks, but he also works on other aspects of supernova remnants, isolated neutron stars, magnetars, pulsar wind nebulae, clusters of galaxies and AGN. He is H.E.S.S. working group leader for supernova remnant and pulsar wind nebula research, and a science member of CTA, the  X-ray spectroscopy mission XRISM, and the X-ray polarisation mission IXPE. His scientific achievements include: providing first evidence for magnetic field amplification near supernova remnant shocks; the first detection of 68 keV and 78 keV line emission from radio-active titanium; the discovery of the Si-rich X-ray jets in Cas A; showing that magnetars magnetic fields are not caused by rapid initial rotation.