1. Observations of SNR RX J0852.0-2644 with CANGAROO-II telescope Kyoto, Dec., 16, 2003 H. Katagiri, R. Enomoto, M. Mori, L. Ksenofontov Institute for cosmic ray research (ICRR)

2. Introduction But claimed by Butt et al. and Reimer et al. … TeV  detection from SNRs SN1006 (CANGAROO) => e or p Cas-A (HEGRA) => p RX J1713.2-3946 (CANGAROO) => p RX J1713.2-3946 Inconclusive problem Need further evidence NANTEN supports our results (Fukui et al.)

3. ROSAT X-ray image 8o8o Vela SNR Maximum X-ray emission 2o2o SNR RX J0852.0-4622 Flux (photons/sec/keV) (0.4<E<2.0keV) Energy (keV) 1510

4. Radio Parkes 4.85GHz survey image(gray scale) Weak emission S ν at 1GHz =47±12Jy =>same as RXJ1713,SN1006. Spectral index  =0.40  0.15

5. Molecular clouds Vela SNR taken by NANTEN and soft X- ray image(gray scale) taken by ROSAT. Around Vela Molecular ridge taken by the Colombia University 1.2m millimeter-wave telescope. Vela region CO integrated Intensity map NANTEN

6. EGRET No point source in CANGAROO FOV Effected by Vela SNR and pulsar (2.5deg. distance)

7. Profiles of RX J0852.0-4622 On the galactic plane => molecular clouds (l,b)=(266.2,-1.2) Type II SNR Density within SNR n stellar-wind cavity Ti line Column density from X-ray angular size Distance < 500pc Age  1000 yr

8. CANGAROO observations NW rim with maximum X-ray emission ( ,  )=(132.25,-45.65) Minimum zenith angle  14.6 o => Energy threshold 500GeV Observation term 2002 and 2003 ON 97h OFF(background) 89h Stereoscopic observation with 2 telescopes (2003) => under analysis CANGAROO-II 10m IACT in Australia

9. Procedure of analysis 1.Select clustered event =>remove N.S.B. 2.Arrival time of signal Almost the same time at shower event 3.Cut cloudy data 4.Cut low elevation data 5.Cut hot pixels N.S.B.

10. Image analysis Source position Distance Width Length Alpha Width and Length are the R.M.S. of the ADC counts on each axis. In order to reject cosmic ray events as a noise

11. Gamma-ray signal (ON-OFF) 8.0  Results

12. Morphology Consistent with X- ray and radio PSF Seems to be Point source Blue:our data Red:ASCA X-ray data Green:4850MHz continuum

13. (  -function approximation) Synchrotron/inverse Compton model Source spectrum Differential flux of photons from the energy loss of electron Electron energy Mass of the electron Spectral index Maximum accelerated energy of electrons Volume of emission region Distance from the earth Average time that an electron ( ) emits a photon ( )

14. Inverse Compton process Lorentz factor of electrons Cross section of Thomson scattering Energy density of CMB

15. Synchrotron process

16. One-zone model: EGRET: Diffuse emission  Upper limits (counts + 2  )

17. Two-zone model: “Simple”

18. Difficulty in two-zone model

19. X-ray TeV Need Chandra, XMM-newton results (filaments ?) and more exact discussion (escape time, energy loss process) (Aharonian, Atoyan, and Kifune) Too many parameters!!! Two-zone model:

20. model (Naito-Takahara model) to

21. Intensity of protons Differential cross section Low energy: isobar model High energy: scaling model

22. Fitting parameters Data CANGAROO EGRET diffuse (upper limits) Best fit

23. Best fit model :solid angle of the observed part

24. Summary Our data strongly favour gamma rays from neutral pions and low flux from synchrotron/inverse Compton. NANTEN data will give us more physics. Fine structure allow two-zone model. Chandra and XMM-newton resutlts are needed.

25. Check of approximation Factor is 1.5, but it does not change conclusion. RX J1713.2-3946 Full calculation Delta function approximation