Status of CANGAROO III 1.Introduction 2.Resent Results - - PDF document
Status of CANGAROO III 1.Introduction 2.Resent Results 3.Brand-new! CANGAROO T2 Akihiro Asahara ( Kyoto Univ.) 4.Stereo Analysis CANGAROO expanded meeting C ollaboration of A ustralia and N ippon for a GA mma R ay O bservatory in the O utback
1.Introduction 2.Resent Results 3.Brand-new! CANGAROO T2 4.Stereo Analysis
An array of imaging atmospheric Cherenkov telescopes to detect high- energy gamma-rays from celestial
University of Adelaide Australian National University Ibaraki University Ibaraki Prefectural University Kanagawa University Konan University Kyoto University Nagoya University National Astronomical Observatory of Japan Osaka city University The University of Tokyo (ICRR) Shinshu University Institute for Space and Aeronautical Science Tokai University Tokyo Institute of Technology Yamagata University Yamanashi Gakuin University
Gamma-ray simulation Proton simulation
Camera image
Gamma Proton
α distribution
（ simulation）
Observation Data (Crab Nebula)
OFF run ON run Residual
(March 2000) 552ch PMTs
Grade A (>5sigma, multiple) Grade B (>5sigma) Grade C (strong but with some qualifications) CANGAROO FOV (El > 40 degree)
NGC253 1 Starburst galaxy Cen X-3 1 X-ray Binary SN1006 Cas A RX J1713.7-3946 3 Supernova remnants Mrk 421 Mrk501 1ES2344+514 PKS2155-304 3C66A BL Lac 1H1426+428 1ES1959+65 8 Blazars Crab Vela PSR 1706-44 3 Pulsar nebulae Red: Grade A Blue: Grade B Black: Grade C
Hard to explain by emission from electrons (Brems, IC) ⇒Emission from protons(π0)? ⇒ Cosmic ray origin?
Enomoto et al. Nature 2002
New kind of TeV source Similar in size to our own galaxy Nearby spiral galaxy (2.4Mpc) Broad emission region.
Itoh et al. A&AL 2002 Radio CANGAROO
Non-thermal radiation from Galactic Halo
Optical Multi-wave-length spectrum of Galactic Halo Itoh et al. ApJL 2003
Fewer IR background photons?
Okumura et al. ApJL 2002 Gamma-ray Emission above 20 TeV Cosmology: galaxy formation 5TeV
Peak intensity of detected TeV gamma-ray flux becomes ten times stronger than that of X-ray flux from the nebula. TeV gamma-ray flux is difficult to explain by Sync-IC (2.7k CMB) model in the nebula.
Chandra ACIS Image (0.7-9 keV)
Kushida, 2003, Ph. D thesis, Tokyo Inst. of Tech. The magnetic field is too week.
SNR/Pulsar Crab SNR SN 1006 SNR RCW 86 SNR RX J0852-4622 SN 1987A PSR 1259-63/SS2833 PSR 1509-58 PSR 1420-6048 Vela pulsar AGN PKS 2155-304, PKS 2005-489 AGN PKS 0548-322 EXO 055625-3838.6 Galactic Center/Sgr A* Galactic jet object SS433 Galaxy The Small Magellanic Cloud EGRET un-ID 3EG J1234-1318
Detected Upper limit Positive
Signal Status
On analysis On analysis On analysis On analysis On analysis Finished; In prep. Finished; In prep. Finished; In prep. On analysis On analysis On analysis On analysis On analysis On analysis On analysis Finished
Caution! This is prospective image.
10m X 2 10m X 3 10m X 4 Sep 2003 EXO 0556 RX J0852 Stereo Targets RCW86 SN1006 PSR 1706, RXJ 1713 Observation
Better angular resolution ∆θ=0.25°(One month observation)→ 0.15°(event by event) Better energy resolution ∆E/E=30%→15% And improvement of S/N ratio.
0.25 deg (Single)
SN1006 significance map (CANGAROO 10m single)
TeV γ-rays from shell-type SNRs
0.05 deg (Stereo)
Single Telescope ~0.25deg (one month observation)
10m X 2 Stereo Telescope ~0.15deg (event by event) ~0.05deg, or better than that!! (one month observation) Alpha <15゜ 952±137events(6.9σ) 0.45<E(TeV)<6.25
Stereo observation Effective area → ×0.8 S/N → ×6 ～7 (Enomoto et al. 2002)
750±60 (12σ)
Started operation in
Assembled in
In operation since 2000 Second Telescope (CANGAROO T2) Third Telescope (CANGAROO T3) First Telescope (CANGAROO T1)
Completed in 2002 Focal length 8m Improved FRP mirror segments 427ch imaging camera Placed Hex; FOV 4.0 HV imposed on each PMTs
ADC TDC PMT hit Scaler Star Info.
DAQ phase I (current): Both telescopes are operated Independently. Attached information on T2 data:
T1: trigger rate ~ 40Hz T2: trigger rate ~ 30Hz
T1 rate after cut ~2Hz The Stereo trigger rate is limited by T1.
Measured by TDC Calculated from Telescope movement OFF-line stereo analysis is working well.
Red: ADC spectrum of T2 Blue: ADC spectrum of T2 made from the data triggered by T1 Pink: Power law function (index -2.7) Eth(blue) / Eth(red) ~ 4 T2 Energy threshold ~ 200GeV
TDC (hit timing) ADC (light intensity) T1 T2
Typical Observation time (ON-OFF total): 8 0 h/ m onth 0.01Crab (@200GeV)
And we have several papers in prep. Second Telescope is in expected performance. Energy threshold ~ 200GeV Sensitivity will become ~ 0.01Crab (@200GeV, 20 hour).