Polarized Radio Emission within Pulsar Magnetosphere & Pulsar Observation with JMS 66m PengFei Wang PengFei Wang ( 王鹏飞 )NAOC

Outline: I.Emission of polarized waves II.Propagation of polarized waves within pulsar magnetosphere III.On the frequency dependence of pulsar emission beam IV.On the frequency dependence of pulsar linear polarization V.Pulsar Observation with JMS 66m

P.F. Wang, C. Wang and J.L. Han, 2012, MNRAS, 423, 2464 Observation facts ： Problem: The physical origins for various polarization features are not clear! I.Emission of Polarized waves Strong L.P. Strong C.P. Single sign of CP Sense reversal of CP “S” shaped PA curve Orthogonal Modes Research contents : 1. Get magnetic field geometry; 2. Calculate the acceleration and emission process of relativistic particles; 3. Obtain the distributions for the polarized intensities and polarized pulse profiles.

Polarization patterns I L V P.F. Wang, C. Wang and J.L. Han, 2012, MNRAS, 423, 2464 I.Emission of Polarized waves Polarized pulse profiles Polarized intensity distribution Sense of CP Conclusions: 1.Describe the polarized emission process explicitly for the first time; 2.Determine the polarization features for different density models; 3.Propose a new mechanism for CP production.

Physical picture ： 1 ） Rotating dipole magnetosphere B * =10 12 G 2 ） Relativistic e e + streaming out along open magnetic field lines, with density N/N GJ ~ 500, and energy γ ~ 400 Ω μ k B Propagation effects 1 ） O mode Refraction 2 ） Adiabatic Walking 3 ） Wave mode Coupling 4 ） Cyclotron Absorption Emission 1 ） Curvature Radiation 2 ） Co-rotation Influences Problem ： The polarized waves need to propagate out of pulsar magnetosphere to be detected. P.F. Wang, C. Wang and J.L. Han, 2014, MNRAS, 441, 1943 II.Propagation of polarized waves Research contents: 1. Jointly investigate the polarized emission and propagation processes; 2. Explain various polarization features.

P.F. Wang, C. Wang and J.L. Han, 2014, MNRAS, 441, 1943 II.Propagation of polarized waves Without rotationWith rotation X O Total Polarization XO Evolution of polarized Waves Polarized waves within 1/γ cone Emission within pulsar beam Polarized pulse profiles Without rotation With rotation Conclusions: 1.Demonstrate the influences of various propagation effects; 2.Explain the orthogonal modes and highly polarized radiation; 3.Explain the correlation between the sense of CP and PA.

P.F. Wang, J. L. Han and C. Wang, 2013, ApJ, 768, 114 k = -0.1~-0.9 θ 0 = 1 o ~6 o Low Freq High Freq III.Frequency dependence of pulsar emission beam Observation facts ： Problem ： 1. Observations show a large range of power law index k, inconsistent with theoretical predictions; 2. No theory predicts θ 0 Research contents: 1. Consider the density and energy distributions of relativistic particles; 2. Simulate pulse profiles for various frequencies by considering the curvature radiation mechanism.

Uniform 0.4 GHz Conal Patch Density modalEmission Intensity Pulse Profile Freq. Dependence 1. Two components merger at higher frequency; 2. k approximates -1, same as simplified analysis. 1.The emission is low at the central parts from higher magnetosphere. 2. Aberration & Retardation lead to the asymmetry of pulsar profiles. III.Frequency dependence of pulsar emission beam Conclusions: 1.Determine the co-relation between the profile evolution and the energy and density distributions of relativistic particles; 2.Explain the minimum beam angle at the highest frequency; 3.Supports the patchy density model instead of cone and core.

IV.Frequency dependence of pulsar linear polarization Observation facts ： Problem ： 1. What is the reason for the frequency dependence of linear polarization? 2. Does it relate to the frequency dependence of profile width? Research contents: 1. Jointly investigate the polarized emission process and propagation effects; 2. Calculate the mode distributions within pulsar beam, polarized pulse profiles and their evolution with frequency. P.F. Wang, C. Wang and J.L. Han, 2015, MNRAS, 448, 771 Fractional linear polarization Profile width Low Freq High Freq

IV.Frequency dependence of pulsar linear polarization P.F. Wang, C. Wang and J.L. Han, 2015, MNRAS, 448, 771 Emission Patterns for Ix, Io and L% 800MHz 1.4GHz 2.4GHz Polarized pulse profiles Freq. dependence of profile width and LP Conclusions: 1.Depict the wave mode distributions within the entire pulsar beam and the depolarization mechanism; 2.Demonstrate the effects of rotation, refraction and adiabatic walking on the wave mode distributions; 3.Explain the frequency dependence of fractional linear polarization for some pulsars.

V.JMS 66m Pulsar Observations Telescope ： JMS66m Receiver: A. S, BW-150MHz( MHz), Tsys~75K B. X, BW-180MHz( MHz), Tsys~80K Backend: PSR-V1.3 (South East University), Observation modes A. 150MHzBW ， 256CH ， 0.2ms B. 289MHzBW ， 248CH ， 0.2ms C. 150MHzBW ， 128CH ， 0.1ms Observations: I Check the performance of the pulsar backend; Make sure pulsars can be detected. II Test various observation modes of the backend; Check how many pulsars can be detected at S and X. JMS 66m PSR-V1.3 (Xilinx V5)

Calibrating Sources: 3C483C348 3C286 3C147

PSR B Phase--Frequency Phase--Time XS

PSR B SX Phase--Frequency Phase--Time

PSR B SX Phase--Frequency Phase--Time

MSP J Observation mode: 150MBW--128CH--0.1ms; RFI in the frequency channels and time bins have not been clipped. Phase--FrequencyPhase--Time S

V.JMS 66m Pulsar Observations Observation summary: Each source is observed for more than half an hour. I. X band, observed 17, detected 8 (Large Tsys and Small BW); II. S band, observed 34, detected 28; III. JMS 66m did well in observing pulsars at S band, the pulsar backend developed by South East University also has good performance. Further works: I. RFI removal; II. Flux calibration; III. Scientific analysis.

Thank you!