摘要
Based the Alfven wave oscillation model(AWOM)and relativistic precession model(RPM)for twin kHz QPOs,we estimate the emission positions of most detected kHz QPOs to be at r=18+/-3 km(R/15 km),except Cir X-1 at r-30+/-5 km(R/15 km).For the proposed Keplerian frequency as an upper limit to kHz QPO,the spin effects in Kerr Spacetime are discussed,which have about a 5%(2%)modification for that of the Schwarzchild case for the spin frequency of 1000(400)Hz.The application to the four typical QPO sources,Cir X-1,Sco X-1,SAX J1808.4-3658 and XTE 1807-294,is mentioned.
基金
supported by the National Basic Research Program of China(Grant No.2009CB824800)
the National Natural Science Foundation of China(Grant No.10773017)
