Chandraによる SN1006衝撃波面の詳細観測 SN 1006 with ASCA 馬場 彩、山崎 了、植野 優、小山 勝二 (京都大学)

1. Introduction “How are cosmic rays accelerated up to TeV?” Basic concept: Diffusive Shock Acceleration (DSA) (Bell 1978; Blandford & Ostriker 1978…) Koyama et al.(1995) Discovery of synchrotron X-rays from the shell of SN 1006 SN1006: type Ia d=1.8kpc 10´ Next problem: More realistic model “How do the non-thermal electrons distribute on the shock?” Spatial and spectral studies with Chandra

1.2. Chandraの特長 Chandra ACIS-Sで観測 (68 ksec) 高空間分解能 位置分解能 ～ 0.5″! → 衝撃波前後面の詳細構造が分かる 2. 低エネルギーまで感度あり 0.3 keV – 10.0 keVに感度 (ACIS-S) → 酸素のラインも見ることが出来る (特に低温プラズマの診断に有利) Chandra ACIS-Sで観測 (68 ksec)

2.1. Image and spectrum thermal non-thermal extended sharp outward = upstream 2.1. Image and spectrum Energy (keV) 1 5 0.3 inward = downstream thermal extended non-thermal sharp SN1006 NE shell How large are the scale length of non-thermal component? 0.3 – 2.0 keV 2.0 – 10.0 keV

2.2. Analyses method We want to know: upstream downstream the scale length of non-thermal component in outward = upstream inward = downstream 40 shock counts 20 wu wd 2.0 – 10.0 keV arcsec 20 40

2.3. Fitting results Upstream 0.04 pc 0.01 pc Downstream 0.2 pc 2 – 10 keV Upstream 0.04 pc 0.01 pc Downstream 0.2 pc 0.05 pc Mean value………………. Minimum value……….…..

3.1. Discussion (1) the observed and derived parameters Observed parameters: Derived parameters from DSA: Emax , Bd 1. The wide band spectrum nbreak = 2.6 x1017 Hz +0.7 -0.7 EmaxBd0.5 = 0.37 erg G0.5 +0.04 -0.06 2. The diffusion coefficient K wu = Ku uu wd = Kd ud K = xEmaxc 3eB x ~ > 1 B dB Emax Bd > 6.4x106erg/G uu = 4ud = us = 2600 km/s (Winkler & Long 1997) 3. The acceleration and loss tacc = = 1010s 4(Ku+Kd) us2 tacc < tsync EmaxBd2 < 6.5x10-8 erg G2 tsync= 6.3x102Emax-1Bd-2

3.2. Discussion (2) the Emax – Bd relation log (Emax/eV) 14 13 log (Bd/G) -6 -3 from nbreak from Kd and x from tacc Emax ~ 30 TeV Bd ~ 30 mG xd < 1.3 shock Bd ? Highly turbulent magnetic field! downstream e-

3.3. Discussion (3) in upstream Emax ~ 30 TeV Bd ~ 30 mG Bd < Bu < Bd 1 4 7 mG < Bu < 30 mG The gyro radius in upstream rg: Emax eBu 0.001 pc < rg = < 0.005 pc ~ wumin = 0.01 pc ! shock Conventional DSA cannot explain the result. Bu Bd the magnetic field in upstream nearly parallel to shock plane the new acceleration mechanism e.g. Surfing acceleration (Hoshino & Shimada 2002) downstream Further analyses of SN 1006 and other SNRs

4. Other SNRs (1) Young SNRs Cas A Kepler Tycho 0.06pc 0.04pc 0.01pc 0.007pc 0.02pc 0.02pc

4. Other SNRs(2) middle aged SNRs RCW86 0.5pc 0.1pc 0.6pc 0.08pc

5. Summary We resolved non-thermal emission from thermal plasma in spatially and spectroscopically. 2. The non-thermal filaments have very small scale length! 3. The conventional DSA should be revised to explain the small scale length. the magnetic field parallel to shock plane in upstream? new acceleration mechanism? or 4. The analyses of other SNRs is important!