Modeling Multi-wavelength Pulse Profiles for PSR B1821-24 Du, Qiao et al. 2015, ApJ, 801, 131 Modeling Multi-wavelength Pulse Profiles for PSR B1821-24 Yuanjie Du (杜源杰) Qian Xuesen Laboratory of Space Technology 钱学森空间技术实验室（航天五院） 2015-7-4

Background Introduction Modeling Results Conclusion & Remark Outline Background Introduction Modeling Results Conclusion & Remark 钱学森空间技术实验室

Background Introduction — PSR B1821-24 Located at the Globular Cluster M28 (d~5 kpc) P=3.05 ms；Pdot=1.62E-18 s/s （6th largest in MSPs, useful for navigation） The largest Edot (2.2E36 erg/s) Giant Pulse (coincident with its first X-ray peak) The first MSP detected a glitch (2001 March)

Background Introduction —— Pulse Profiles Multi-wavelength (radio + X-ray + gamma-ray) Peak Multiplicity Peak Position Peak Separation Caustic models (Outer gap and two-pole caustic models) cannot explain these properties. Johnson et al. 2013, ApJ, 778, 106

Background Introduction Modeling Results Conclusion & Remark Outline Background Introduction Modeling Results Conclusion & Remark

Pulsar Emission Models 外间隙模型 (Cheng、Romani) 极冠模型 (Harding) 双极交脊模型 (Dyks) 狭长间隙 (Harding) 环间隙模型 (Qiao)

Annular Gap Model The open field line region is divided into core gap and annular gap regions by the critical field line. The annular gap radius is much larger for pulsars with short spin periods, and can be a excellent accelerator for pulsar γ-ray emission. If the inclination angle is nonzero, then the width of annular gap varies with magnetic azimuthal, the corresponding emissivity on each field line is therefore different. Ruderman & Sutherland 1975

Modeled Results Du et al. 2015, ApJ, 801, 131

Fit parameters Du et al. 2015, ApJ, 801, 131 Both values of magnetic inclination angle (α) and viewing angle (ζ) are derived from radio polarization measurement, i.e. PA curve fitting.

Shifted Emission heights Single pole Non-caustic radio emission Emission altitudes Du et al. 2015, ApJ, 801, 131 Shifted Emission heights Single pole Non-caustic radio emission

Background Introduction Modeling Results Conclusion & Remark Outline Background Introduction Modeling Results Conclusion & Remark

Conclusion Multi-wavelength (radio, X-ray and γ-ray) pulse profiles can be well reproduced by the single-pole annular gap model with shifted emission altitudes. Radio emission is likely to be generated in a non-caustic mechanism.

Remark-福利来啦！！！ 我们需要有独立科学思想、推动航天技术和高性价比的天文卫星，有核心的可行idea和创新的载荷技术。 若您有好的想法，且愿意，请联系： 杜源杰，航天五院 钱学森空间技术实验室， PI（空间科学探测）、脉冲星应用研究（CI） Email：dyj@nao.cas.cn； Mobile Phone：13426323216 实验室招聘博士和实习生，待遇优厚！欢迎“软硬皆懂”的小牛人来应聘，共同“创业”！

谢谢大家！