磁場散逸を考慮したパルサー星雲の閉じ込めについて Shuta J. Tanaka (Konan Univ.) with K. Toma (Tohoku Univ.) & N. Tominaga (Konan Univ.) 25, Nov., 2017, ~中性子星の観測と理論~ 研究活性化ワークショップ 2017 @ 国立天文台

Introduction

Pulsars & PWNe Pulsar Wind Nebulae (PWNe) are powered by pulsars Crab (Chandra) Pulsar Wind Nebulae (PWNe) are powered by pulsars Pulsed emission ~ a few % of Lspin. Most of Lspin release as relativistic magnetized flow, called pulsar winds. ~ 70 of 2500 pulsars have observable PWNe.

Crab Nebula & Pulsar spectra in radio (Bietenholz+15) PWNe observations Broadband emission from radio to TeV Brighter than pulsar itself. Large angular extent (~ pc in size) Confined by supernova remnant (SNR) Expansion and flux evolution Crab Nebula & Pulsar spectra (Buhler&Blandford14) SNR G21.5-0.9 diff. image (2012-2001) in radio (Bietenholz+15) PWN G21.5-0.9 Filament motion in opt. (Nugent+98) PSR J1833-1034 G21.5-0.9 (Chandra)

σ-problem

Structure of PWNe Light cylinder RLC~108cm Termination Shock SNR G21.5-0.9 PWN G21.5-0.9 Crab (Chandra) Crab (Composite) Crab (HST) PSR J1833-1034 G21.5-0.9 (Chandra) Light cylinder RLC~108cm Termination Shock RTS~ 0.1pc Contact Discontinuity RPWN ~ 2pc Shock Ⅰ Ⅱ Ⅲ Ⅳ Ⅴ pulsar Magneto- sphere Pulsar wind region Pulsar wind nebula (shocked pulsar wind) Shocked SN ejecta Unshocked SN ejecta + ISM vexp << c (vth ~ c) vexp ~ c

Expansion of PWN is much slower (~ 103 km/s) than pulsar wind (~ c) KC model Kennel & Coroniti (1984a, b) (c.f., Rees & Gunn 1974) 1D static MHD model of PWN Expansion of PWN is much slower (~ 103 km/s) than pulsar wind (~ c) magnetization of pulsar wind: σ = particle energy flux / Poynting flux Image of PSR taken from NASA Flow velocity [~ v / c] Distance [r / RTS] Kennel&Coroniti1984a v∞ ~ vexp ~ σ c ~ 103 km/s σ-problem

in radio (Bietenholz+15) Beyond KC model KC model = 1D static MHD model 1D? MHD? static? Crab (Chandra) Porth+14a diff. image (2012-2001) in radio (Bietenholz+15) Lyutikov+10 3D effects (turbulence) & B-field dissipation (non-ideal MHD) are discussed.

Turbulent B-field Crab (Chandra) Shibata+03 Shibata+03 Bucciantini17

Magnetic Dissipation

Minimum torque by Michel’69 Early Simple Models Fireball (Acceleration) KC model of PWN (Deceleration) Low-σ High-σ Minimum torque by Michel’69 (Acceleration)

B-field conversion & dissipation Our Model τdiss : B-field dissipation τconv: B-field conversion Λrad: Radiative cooling TTT17 in prep. TTT17 in prep. TTT17 in prep. c.f., Drenkhan02 TTT17 in prep. TTT17 in prep. TTT17 in prep. B-field conversion & dissipation

Results: 4-velocity σ

KC modelとの比較 Ishizaki+17 Ishizaki+17 TTT17 in prep.

Deceleration of relativistic magnetized outflow is studied. Summary Deceleration of relativistic magnetized outflow is studied. Heuristic model of B-field dissipation is adapted. B-field dissipation leads efficient deceleration of outflow. Multi-dimensional effects are not required for deceleration. Further studies Broadband emission map c.f., Drenkhan02