李兆升 (徐仁新 代实 郭彦君 仝号 冯骅) 北京大学 孤立中子星的XTP模拟 李兆升 (徐仁新 代实 郭彦君 仝号 冯骅) 北京大学

AXP/SGR Low-field magnetars CCO Tong & Xu (2014)

Mereghetti (2008)

Outline 1 Non-thermal Polarization AXP/SGR Strong magentic field ? 2 AXP/SGR (Magnetar) 4U 0142+61 Small glitch or Anti-glitch? SGR 1900+14 Free Precession? 3 CCO (Anti-magnetar) Cas A Period & Pulse Profile 1E 1207.4-5209 Absorption lines(2.1 keV & 2.8 keV?)

Non-thermal Polarization NS-atomsphere (0.1-10 cm) thermal x-ray photons X-mode & O-mode X-mode dominant! Lai & Ho 2003

Resonant Cyclotron Scattering Twisted magnetosphere Absorption plus re-emission  Scattering Thompson et al. 2002

thermal & non-thermal Rea et al. 2008

Polarization RCS X-mode retain its initial polarization state. O-mode -> X-mode Taverna et al. 2013

QED (vacuum polarization) Fernandez et al.2011

Phase-resolved polarization

Fernandez et al.2011

Taverna et al. 2013

Taverna et al. 2013 XIPE

40 ks

GEM/XTP Obs. Time estimation Linear Pol. 3σ 40% 2-4 keV 20% 4-10 keV Pol. Angle 10 deg

自转频率误差估计 Pulse Profile SGR 1900+14 4U 0142+61

4U 0142+61 Anti-glitch or Small glitch? 2ks/2 weeks

SGR 1900+14 Free precession? (Thompson et al. 2000) 2ks/3 weeks

1E 1207.4-5209 Cyclotron absorption lines 2BB*absorption (Sanwal et al. 2002)

Cas A 1% pulse fraction & sinusoidal profile & P=0.1s The 3σ upper limits on the pulsed fraction are ~13% for P>0.3s and 7% for P>3 s (Mereghetti et al. 2002) 1% pulse fraction & sinusoidal profile & P=0.1s ~3σ >10σ

Results AXP/SGR linear polarization 1E 1207.4-5209 Cas A 4U 0142+61 1% pulse fraction & sinusoidal profile 10ks >10σ