Speaker: Shuang-Nan Zhang (IHEP & NAOC)

　　Time & Place: Thursday, 3:00pm, March 13th, Lecture Hall, 3rd floor

　　Abstract: Radio pulsars are the most stable natural clocks in the universe, yet timing noises can still be substantial when the times of arrivals of their pulses are fitted with some well accepted spin-down models or templates of pulsars. In this talk, I will review our recent work on modeling the timing noises of radio pulsars. Our model includes a long-term power-law decay modulated by periodic oscillations of the surface magnetic fields of neutron stars, which can explain the statistical properties of their timing noises. We find that the spin-down evolutions of young and old pulsars are dominated by the power-law decay and periodic oscillations, respectively. By applying our model to the individual spin-down evolutions of many well-measured radio pulsars,we find evidence for Hall drifts and Hall waves in the crusts of neutron stars. Finally we also attempt to improve the sensitivity of detecting gravitational waves with pulsars by applying our model to reduce the timing residuals of millisecond radio pulsars. The main publications related to this talk can be found at this ads link:

　　http://adsabs.harvard.edu/cgi-bin/nph-abs_connect?library&libname=pulsar+timing&libid=44cf02882f

　　Biog: Bachelor from Tsinghua University in 1979. PhD from University of Southampton in1989. Postdoc at University of Pennsylvania from 1989 to 1992. Research scientist at NASA Marshall Space Flight Center from 1992 to 1998. Faculty at University of Alabama in Huntsville from 1998 to 2002. Distinguished professor in Tsinghua University from 2002 to 2009. Since 2009, director of Key Laboratory of Particle Astrophysics and Center for Particle Astrophysics, Institute of High Energy Physics, and chief scientist of Space Science Division and director of the X-ray Imaging Laboratory, National Astronomical Observatories of China, Chinese Academy of Sciences. His research fields include black hole and neutron star X-raybinaries, microquasars, radiopulsars,active galactic nuclei, general relativity, cosmology, space X-ray instrumentation. He has over 200 refereed papers with more than 5000 citations, which can be accessed here:

　　http://adsabs.harvard.edu/cgi-bin/nph-abs_connect?library&libname=2006-08-01&libid=44cf02882f