Koyama and Bamba Non-thermal Filaments from SNR

1.Introduction of X-ray study of cosmic ray acceleration in SNRs 2.Chandra observation of SN Discussion of acceleration parameters; time scale, magnetic field, and maximum energy of electrons 4.Application to other SNRs 5.Summary 6.Hints for observations of SNRs interacting with molecular clouds

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 sync. X-rays from the shell of SN 1006 Next: More direct measurements Spatial and spectral capability of Chandra SN1006: type Ia d=2.18kpc 10 ´ B, E max, distribution of electrons on the shock….. SNRs with sync. X-rays More sample SNRs

2.1. Chandra Image and spectrum How wide are the non-thermal filaments? 0.3 – 2.0 keV 2.0 – 10.0 keV inward = downstream outward = upstream SN1006 NE shell Energy (keV) thermal extended non-thermal sharp (Bamba et al. 2003)

2.2. Properties of the Filaments 1. Width of non-thermal X-ray filaments Distance : 2.18 kpc (Winkler et al. 2003) w u = pc w d = pc Scale length of nonthermal X-rays arcsec upstreamdownstream wdwd counts – 10.0 keV wuwu shock 2. Wide band spectrum (SRCUT model) ν roll = (2.6±0.7)×10 17 Hz Reynolds & Keohane (1999)

u u = 4u d =2890 km/s m.f.p. of e =  r g 3.1. Discussion: three time scales 1. t age : The age of SN 1006 ~ 10 3 years 2. t loss : energy loss time scale (synch. loss) 3. t acc : acceleration time scale  ~ > 1 dB B -2 shockB  up down E max, B

3.2. From equations to parameters A. Age limited case B. Loss limited case t acc = t age < t loss t loss = t acc < t age w u = K u /u u w d = K d /u d w u = min {K u /u u, (K u t cool ) 1/2 } w d = max {u d t cool, (K d t cool ) 1/2 } unknown parameters: E max, B u, B d,  u,  d,  known parameters: u u, rolloff, w u,w d B d = B u (cos 2  + r 2 sin 2  ) 1/2 lolloff ~ BE 2  d <  u Both cases, Restriction of parameters!

3.2.A. Age limited case: t acc =t age <t loss w u =K u /u u, w d =K d /u d dd w u = pc w d = pc B d ~ 78  G E max = 22-29TeV d<ud<u uu  = 0 o t acc <t loss

On the other angle….  d ~ 1 B d = 14 – 78  G E max = 22 – 69 TeV uu  = 60 o  = 30 o dd dd  = 90 o uu

3.2.B. Loss limited case: t acc =t loss <t age w u = min {K u /u u, (K u t cool ) 1/2 } w d = max {u d t cool, (K d t cool ) 1/2 }  < 30 o,  d ~  u ~ 1 B d = 23 – 85  G, E max ~ 21 – 54 TeV  = 30 o uu  = 0 o uu dd

Age limited case;  d ~ 1 B d = 14 – 78  G E max = 22 – 69 TeV Loss limited case;  < 30 o  d ~  u ~ 1 B d = 23 – 85  G E max = 21 – 54 TeV In the future, B d : fully turbulent (Bohm limit) 14 – 85  G B u : 3.5 – 85  G E max : 20 – 70 TeV Anyway, More detailed models Multi-wavelength obs. accurate accel. history CANGAROO suggests B ~ a few  G. (Tanimori et al. 2001) 3.3. Given restrictions for SN 1006 shockB updown In age limited case!

4.1. Application to the other SNR Is SN1006 the lonely SNR with non-thermal filaments? ……No! Vink & Laming (2003) found non- thermal filaments in Cas A Cas A 1 ‘= 1 pc Spatial resolution of Chandra w d =0.024 pc w u =0.017 pc

Tycho Hwang et al. (2002) 30“ = 0.3pc w d =0.079 pc w u =0.015 pc “filaments with small E.W.”  = The filament is non-thermal!

Kepler 30“ = 0.7pc w d =0.019 pc w u =0.024 pc w d =0.069 pc w u =0.038 pc  =  = Energy (keV) 1510 Energy (keV) 1510 Thin & non-thermal Filaments!!  =

4.2. The scale length vs. radius Radius of SNR (pc) Scale length (pc) downstream upstream The scale length is ~ % of the radius. The scale lengths grow larger as the SNRs age. Cas A 30 Dor C RCW 86 SN 1006 Kepler Tycho

5. Summary 1.Non-thermal and thin filaments are discovered at the outer edge of SN The scale length is very small, w u = 0.01 – 0.1 pc and w d = 0.06 – 0.4 pc. 3.Both in age limited case and loss limited case, we can make restrictions such as; magnetic field in downstream is turbulent. electrons are accelerated to 20 – 70 TeV. 4.We found thin non-thermal filaments in many SNRs. 5.The filaments glow wider as SNRs age older.

6. Hints for observations of SNRs interacting with MCs G , W28, RCW 86…. RCW 86 G What determines the scale length?

4. Application to other SNRs Do other SNRs have non-thermal filaments? Cas AKeplerTycho 0.02pc 0.04pc 0.007pc 0.02pc 0.06pc 0.01pc Many SNRs have thin filaments!