A New Aspect of the Crab Pulsar Nebula; Particle Acceleration and Heating Shibata, S., Tomatsuri, H., Shimanuki, M., Saito, K. Nakamura, Y., (Yamagata University) And Mori, K.(Pennsylvania State University) at Pusan National University, 2002 Nov. 18

Previous View of the Crab Nebula 1 SN 1054 Synchrotron (Shklovskii 1953, Vashakidze 1954, Dombrovsky 1954) 33ms Pulsar; energy source (radio pulsar 1967; Hewish et al.1968; Staelin and Reifenstein 1968) L_rot = 5 x erg/s

Previous View of the Crab Nebula 2 Magnetic field; pulsar origin ； toroidal field (Aschenbach & Brinkmann 1975); Disc wind? Makishima et al. 1981

Previous View of the Crab Nebula 3 Synchrotron Luminosity and spectrum R-Shock Equipartition field B ～ 0.2 mG γ ～１０ ６ Particle flux ～１０ ２８ /s

Previous View of the Crab Nebula 4 Kennel & Cornoniti 1984; acceleration efficiency of the wind = 99.7% Kinetic energy >> EM Energy Toroidal Field Ideal MHD EM KE Fast Shock B ～ 0.2 mG γ ～１０ ６ Particle flux ～１０ ２８ /s = σ ～１０ －３ EM KE

Fig. 1 Spectral model with KC parameters. (Atoyan & Aharonian, 1996). If σ<<1, Plasma is heated and accelerated at the shock flow, and the nebula shines well. In the post shock flow, P gas >>P mag 、 sub-fast, flow speed down, field increases, so Bright at R_nebula ～ R_shock σ -1/2 Wind theory （ relativisitc Centrifugal wind ) σ<<1 mistery

Chandra Observation -Disc and Jet -Wisp speed -Spatially resolved spectra Wisp velocity 0.45 c The kinetic-energy dominant wind shocks and shines Ｍｏｒｉ ２００２

This work If one extends the Kennel & Coroniti (KC) model to 3D, does one can understand the Chandra observation? (intuitively) the assumptions taken in KC model may be unjustified; the result of σ<<1 might also be unjustified. The nebula can be dissipative (acceleration and heating inside of the nebula

A 3D model KC model Ideal-MHD (frozen-in) condition holds Toroidal field approximation Disc wind is assumed but

log f [partcile /cm 3 /str] ε * = ε/mc 2 low energy particles → adiabatic loss high energy particles → synchrotron loss R * = 1.0 R * = 5.0 R * = 10.0 R * = 20.0R * = 30.0 synchrotoron burn-off energy Input parameter Lw = 5.0 × erg/sec Rs = 3 × cm γ w = u 1 = 3 × 10 6 (isotropic) We calculate f(γ) under the KC flow

Volume emissivity j’ θ´ is the pitch angle of the particle which move towards us Doppler boost Intensity YZ plane = sky coordinate

Suppose what kind of image ？ Disc Wind is assumed, so ring? Due to Doppler boost in expanding flow, fore side is brighter ？

Reproduced Image Lip-shaped; due to pure toroidal field (pitch angle effect) Turbulent field, magnitude of which is as same as roidal component ！

We need ～ 0.2 c flow with σ=0.003, v ～ c Brightness Contrast （ keV ） （ Weisskopf et al.2000) Reproduced image Contrast ～１．３ Contrast ～ ５．５

Flow speed σ ＝ Magnetic Field σ ＝ distance Rs 10Rs distance Bright region should locate where flow is decelerated as far as ideal- MHD+σ<<1

Reproduction of spectra (preliminary) (Mori 2002) (present work) Chandra observation 3D KC model Brightness Photon index Log I_ν Photon index

Conclusion （ A New Aspect of the Crab Nebula comes out ） Spatially resolved spectra are reproduced well with the KC flow. Image is lip-shaped, indicating disordered field: far from pure toroidal Doppler boost does not account for brightness contrast between fore and back sides

Stronger magnetic field and faster nebula flow σ=1-0.1 ； Magnetic reconnection ；  high constrast  fast flow (0.45c) then decelerated (Hester 2002) Discussion  Not Ｌｉｐ, but Ring  Disc is naturally formed

A new model will be constracted ； dissipation of the magnetic field ３Ｄ modeling Thank you