Polarization measurements n Radio telescopes usually take measurements

中国科学院新疆天文台 Polarization measurements n Radio telescopes usually take measurements in two orthogonal polarizations. n For a dual-linear feed n For a dual-circular feed

中国科学院新疆天文台 脉冲星的周期分布 Normal pulsars Millisecond pulsars

中国科学院新疆天文台 P-Pdot diagram Harding 2013

中国科学院新疆天文台 Duty cycle (W/P) Kramer et al. 1998

中国科学院新疆天文台 Pulsar emission beam Gil et al. 1984

中国科学院新疆天文台 Opening angle Kramer et al. 1998

中国科学院新疆天文台 Interpulse n The secondary pulses separated by about 180°from the main pulse. n The main pulse and interpulse originate from oppsite magnetic poles. n While only about 2% of all normal pulsars are known to exhibit interpulses or pre- or postcursors, about 36% of all Galactic MSPs known either emit a post or precursor or exhibit an interpulse. Kramer et al. 1998

中国科学院新疆天文台 Rotating Vector Model （Radhakrishnan & Cooke 1969） Von Hoensbroech & Xilouris 1997

中国科学院新疆天文台 Polarization similarity Han et al. 2009 Ord et al. 2004

中国科学院新疆天文台 Parkes Pulsar Timing Array project

中国科学院新疆天文台 PA variations with time n Long-term changes in pulsar PAs can result from changes in the polarization of the emitted radiation or from changes in the RM along the path. PA=RM·λ 2 n Intrinsic PA changes could result from precession of the pulsar spin axis or changes in the magnetic configuration of the star. n RM changes can occur as the path to the pulsar traverses different regions of the interstellar medium (ISM) or in certain changes the Earth’s ionosphere.

中国科学院新疆天文台 Vela pulsar (PSR B 0833 -45) n discovered in 1968, 89 ms n near the center of the Vela nebula n Hamilton et al. 1985

中国科学院新疆天文台 双脉冲星系统 J 0737 -3039 n discovered in 2003, 22. 7 ms, 2. 77 s n a laboratory for strong-field gravity and plasma physics Yuen et al. 2012

中国科学院新疆天文台 PA variations for PPTA pulsars Yan et al. 2011 b

中国科学院新疆天文台 Thanks for your attention!