报告人:Mohammadreza Zakeri,University of California
时间:
11
月1日(周三)15:00
单位:中科院理论物理研究所
地点:Room 6420, ITP New Building
The [SU(3)]^4 quartification model of Babu, Ma, and Willenbrock (BMW), proposed in 2003, predicts a confining leptonic color SU(2) gauge symmetry, which becomes strong at the keV scale. It also predicts the existence of three families of half-charged leptons (hemions) below the TeV scale. These hemions are confined to form bound states which are not so easy to discover at the Large Hadron Collider (LHC). However, just as J/ψ and
ϒ
appeared as sharp resonances in e
−
e+ colliders of the 20th century, th
e corresponding "hemionium" states are expected at a future e
−
e+ collider of the 21st century.
8
The most powerful jets and winds in microquasars
报告人:Roberto Soria,NAOC
时间:
11
月2日(周四)14:00
单位:
清华大学物理系
地点:蒙民伟科技南楼 S727
At the highest accretion rates (above the classical Eddington limit), theoretical models and numerical simulations predict that stellar-mass black holes and neutron stars release a significant fraction of accretion power via jets and winds. Identifying examples of such powerful outflows, and measuring their kinetic power, is not as simple as identifying the most luminous X-ray sources in a survey. I will illustrate examples of ultraminous X-ray sources where the presence of thick winds is revealed from downscattering, lines and edges imprinted on the observed X-ray spectrum. I will then show examples of huge shock-ionized nebulae (size > 100 pc) around some sources: we measure the expansion velocity of the bubble and the emission from diagnostic lines to estimate the power injected by the accreting compact object. In some cases, such bubbles are also associated with radio synchrotron bubbles. Finally, I will discuss whether the jet and wind power may provide a clue to distinguish between neutron star and black hole accretors.