Variability in X-ray Binaries
Speaker: Prof. Yi Chou 周翊
National Central University
Time: 15:30pm 27th April, 2018 (Friday)
Venue: R521, IoA, 2nd General Building 綜二館R521
An X-ray binary is an accreting binary system with either a neutron star or a stellar size black hole as accretor. The time scales of variability of X-ray binaries ranging from less than a millisecond to thousands of days can be periodic, quasi-periodic or even aperiodic. Investigating on the variability with various time scales of X-ray binaries allow us to probe different parts of systems, including the binary orbits, the accretion disks and the compact objects. In this talk, I will present our achievements in studying the variability of several X-ray binaries recent years. Using the observed-minus-calculated method, we do not only trace the evolutions of orbital and neutron star spin parameters for the partial eclipsing X-ray binary X 1822-371, but also reveal some interesting phenomena for further understanding the natures of this system. For the non-stationary periodic variations, we adopt Hilbert-Huang transfer, a newly developed time-frequency analysis tool which was rarely applied in astronomy before, to resolve the superorbital modulation of SMC X-, the ~4 Hz quasi-periodic oscillation (QPO) of black hole binary XTE J1550-564 and the ~8mHz QPO in neutron star low mass X-ray binary 4U 1636-53.