1 / 16

Magnetic Field Decay and Core Temperature of Magnetars, Normal and MS pulsars

Magnetic Field Decay and Core Temperature of Magnetars, Normal and MS pulsars. Shuang-Nan Zhang 张双南 1 Yi Xie 谢祎 2 1. Institute of High Energy Physics 2. National Astronomical Observatories of China. Evolutionary study of pulsars on p-pdot diagram. B decay required?. Han, J.L, 1997, A&A.

geoff
Download Presentation

Magnetic Field Decay and Core Temperature of Magnetars, Normal and MS pulsars

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Magnetic Field Decay and Core Temperature of Magnetars, Normal and MS pulsars Shuang-Nan Zhang 张双南1 Yi Xie 谢祎2 1. Institute of High Energy Physics 2. National Astronomical Observatories of China

  2. Evolutionary study of pulsars on p-pdot diagram B decay required? Han, J.L, 1997, A&A

  3. Indirect Evidence for B decay? Han, J.L. (1997): power-law decay with “gene”: t0~B0 dependence

  4. Direct Evidence for B Decay Magnetars do not cross death line: normal radio pulsar mechanism works here? Consistent with recent detection of radio magnetars (talks by Manchester and Yuan in this meeting). magnetars Normal pulsars Best fits ms pulsars

  5. P-Pdot or B-Age? Pdot P Derived quantities using B-dipole radiation model (OK if not overwhelmed by pulsar wind loss), but direct comparison with B-decay model. Direct observables: But all tracks calculated using B-dipole radiation model, and indirect comparison with B-decay model.

  6. Inclination angle decay? • Then the observed B-decay may be in fact an illusion of inclination angle decay (Faucher-Giguère & Kaspi 2006; Weltevrede & Johnston 2008). • However, B-decay by 100 times for each kind of pulsars is difficult for inclination angle decay alone. • A better and more physical model required. Magnetic-Dipole radiation model:

  7. B Decay Model: Heyl & Kulkarni, 1998, ApJL The dominant term

  8. ~ Constant Core Temperatures of NSs magnetars normal pulsars ms pulsars

  9. All observed P and Pdot paired randomly All observed P Best fits of real pulsars All observed Pdot General trend of the observed distributions!

  10. Each class of observed P and Pdot paired randomly Model for real pulsars Very similar to the observed distributions!

  11. Completely simulated data: Gaussian distributions Input parameters Model for real pulsars Still very similar to the observed distributions!

  12. Completely simulated data: Not a surprise! Model for real pulsars B-Dipole radiation: Simulated data follow model precisely! For each type of pulsars P=const  Ambipolar B-Decay model (T=const):

  13. Why is the Pdot so small for all pulsars? • B-dipole radiation  • But why the observed Pdot is so small? • Ambipolar diffusion B-decay with constant core temperature  •  P~constant  Pdot must be very small! • This is a natural prediction of the above ambipolar diffusion B-decay model.

  14. Evidence for Hot Magnetars

  15. Evidence for Equilibrium between Heating & Cooling? ?

  16. Summary and Open Questions • No magnetar cross the pulsar’s death line • Normal pulsar radiation mechanism? • All NSs show clear evidence for B-deday • Agrees with ~constant Tcore ambipolar diffusion B-decay model well • Heating by B-decay energy and NS cooling by neutrino and emission in ~equilibrium for all pulsars? • The model naturally predicts very small Pdot as observed • Core temperature: Magnetars 2x108 K, Normal pulsars 2x107 K, ms pulsars 1x105 K • Different populations at birth?

More Related