1. Constraining the Equation Of State (EOS) of neutron stars with eXTP/GDP Long Ji

2. Lattimer, J. M.& Prakash, M. 2001

3. Nicer’s result

4. Target: 1, burst oscillations 2, accreting millisecond pulsars 3, rotation-powered pulsars Light bending : R/M Doppler effect(rotate rapidly) : R Key point : the local radiative model

5. 1. the mass M of the neutron star; 2. the equatorial radius Req of the neutron star; 3. its specific spin angular momentum a ≡ 2πIf c/GM2, where I is its moment of inertia; 4. the inclination i; 5. the observer colatitude of the spot θs; Dimitrios Psaltis 2014 (if ρ <=10°)

6. Ka Ho Lo et al. 2013

7. Low background: ignore Minimum detectable polarization (MDP), 99% confidence level

8. For type-I bursts Plane-parallel symmetry semi-infinite optical depth Chandra 1947

9. flame spreading Spitkovsky, A. et al. 2002

10. flame spreading Spitkovsky, A. et al. 2002

11. K. Viironen and J. Poutanen 2004

12. Results:

15. Summary: GDP do not have enough ability to detect the polarization level during bursts.

16. Accreting millisecond pulsars:

17. Marek Gierlinski et al. 2005 Comp/total flux model A: 0.5-5 keV : 77% 0.5-20 keV : 93% model B: 0.5-5 keV : 40% 0.5-20 keV : 79%

18. Can we distinguish them if we have a larger effective area? Produce a faked spectrum by using model A, and then fit it with model B.

20. thaw kT_bb

21. trapped by a local minimum

22. Gridding the parameter space

23. n: scattering orders tau: optical density K. Viironen and J. Poutanen 2004

24. Summary: GDP is very helpful to decouple the radiative models

25. X-ray pulsars (slow spin) Distinguish different radiation mechanisms

26. Further improvement?

27. Thanks ！！

28. 1. the mass M of the neutron star; 2. the equatorial radius Req of the neutron star; 3. the ellipticity of its surface s; 4. its specific spin angular momentum a ≡ 2πIf c/GM2, where I is its moment of inertia; 5 the quadrupole moment of its spacetime as measured by the parameter η; 6. the inclination i; 7. the observer colatitude of the spot θs; and 8. the angular radius of the spot ρ. Dimitrios Psaltis 2014

29. Observables ： 1 ， flux rms 2 ， the ratio of the fundamental to second harmonic 3 ， color rms 4 ， phase difference Dimitrios Psaltis 2014

30. R 307.28 139.51 norm 21.59 41.85 0.045 0.0091 (0.5-20 1.7429e-09 1.6187e-09) 93% (0.5-20 1.7222e-09 1.3356e-09) 77% (0.5-5 4.4853e-10 5.6668e-10 79%) (0.5-5 2.06e-10 5.139e-10 40%)

31. Dimitrios Psaltis 2014

32. Alessandro Patruno 2009