Post on 21-Jan-2016
description
TeV gamma-ray observation ofTeV gamma-ray observation of RCW86 RCW86
with thewith the CANGAROO-II CANGAROO-II telescopetelescope
WATANABE Shio (Kyoto university)
for the CANGAROO Collaboration
Contents•The CANGAROO telescope•Motivation•Observation •Analysis •Result •Summary
28th ICRC Tsukuba, 3 August 2003
Site: Woomera, South
Australia
CCollaboration of ollaboration of AAustralia and ustralia and NNipponippon
for a for a GAGAmma mma RRay ay OObservatory in the bservatory in the OOutbackutback
University of AdelaideAustralian National UniversityIbaraki UniversityIbaraki Prefectural University of Health
ScienceInstitute for Cosmic Ray Research,
U. TokyoInstitute of Space and Astronautical ScienceKitasato UniversityKonan University
Kyoto UniversityNational Astronomical Observatory
of JapanOsaka City UniversityShinshu UniversitySTE Laboratory, Nagoya UniversityTokai UniversityTokyo Institute of Technology Yamagata UniversityYamanashi Gakuin University
Australian Institutes : 2 & Japanese Institutes : 15
31°06’ S 136°47’ E 160m a.s.l.
—— = — C maxUphoton
dE 4 2 dt I.C. 3
—— = — C max —dE 4 2 B2
dt Synch.3 2
TeV gamma-ray from SNRsTeV gamma-ray from SNRs
0 decay
スペクトルの形に違いSynchrotron
SN1006 NE rim
RX J1713.7-3946 Inverse Compton scattering
=5e13
Naito 1999Naito 1999
Enomoto et al. . 2002
Type-II SNR Diameter 0.8 deg. Distance 2.5 kpc Age ~2000 yr
Supernova Remnant Supernova Remnant RCW86RCW86
ObservedLow temperatureHigh temperatureNon-thermal Bamba et al. 2000
0.5 1 2 5 10[keV]
RCW86 SW shell
Image by ASCASW shell
Red: 0.7 - 2 keVBlue: 2 - 10 keV
Bamba et al. 2000
Multi wavelength spectrumMulti wavelength spectrum
B < 15 µG
Detectable for CANGAROO-II
Radio
RCW86 SW-shellSN1006 NE-rim
X-ray(ASCA)
SN1006 CANGAROO-II 10m Hara et al. 2001
Synchrotron
Inverse Compton scattering (estimated)
Synchrotron emission SN100610
Observation with CANGAROO Observation with CANGAROO
observation selected
ON 26h 23m 20h 29m
OFF 27h 46m 18h 05m
Strongest emission (E>2.0 keV)R.A. = 220.19Dec.=-62.67 (obs.@zenith ~ 32deg.)
2001 (March, April, May)
observation selected
ON 41h 11m 30h 08m
OFF 38h 37m 33h 49m
2002 (March, April)
Suffering from light pollution
Estimation of Threshold Estimation of Threshold EnergyEnergy
Energy threshold[events]
[TeV]
Generated allDetected
Eth 900GeV
32 – 40 degree(relatively large)
High energy threshold
Monte Carlo simulation Gamma-ray
photon index=2.5150 GeV – 15 TeV
Observation zenith angle
Imaging methodImaging method
SumADC -5000ch( -1 TeV)
5000-14000ch(1-2 TeV)
14000ch-(2 TeV- )
Distance 0.1-1.1 0.2-1.1 0.2-1.25
Length 0.05-0.2 0.09-0.25 0.1-0.35
Width 0.03-0.1 0.05-0.14 0.1-0.14
ADC>500(5.4 p.e) & T4a shower event calculate Image Parameter
Energy > 1 TeV (ADC>5000ch)
Excess events577±125(4.6)
Excess events-72±12 (0.6 )
Preliminary ResultPreliminary Result
No excess below 1 TeV inverse Compton scattering ?
Signal <15 deg. Normalize
>30 deg.
Energy < 1 TeV (ADC<5000ch)
Cosmic rayIndex=2.7
SummarySummary
• Supernova remnant RCW86 (emitting synchrotron X-ray) was observed with the CANGAROO-II telescope.
• Preliminarily, we found gamma-ray like events~4 sigma level (@Energy > 1 TeV). – We need more data to confirm this result.
• In this year, we took additional data.– More data
(~65 hours) – High quality
(Stereo observation; Enomoto OG2.5-6)• High Signal/Noise ratio • Lower energy region
Observation in 2003
March Telescope 1 Telescope 2
ON 27h 29m 26h 53m
OFF 23h 47m 20h 16m
April Telescope 1 Telescope 2
ON 42h 20m 37h 41m
OFF 39h 36m 35h 19m
Total Telescope 1 Telescope 2
ON 69h 49m 64h 37m
OFF 63h 23m 55h 35m
X-ray Observation by X-ray Observation by ChandraChandra
High resolution imaging detector
Soft band(<2 keV): DiffusiveHard band(>2 keV): Filament
RCW86 SW shell by Chandra0.5-1 keV 1-2 keV 2-8 keV
Soft and hard regions are completely resolved.
Non-thermalThermal
Rho et al., 2002
Soft
Hard filament
Nearby Molecular Cloud
Red:thermal X-ray
(ROSAT)Contour:
molecular cloud
Multi wavelength spectrumMulti wavelength spectrum
Radio
RCW86 SW-shellSN1006 NE-rim
X-ray(ASCA)
SN1006 CANGAROO-II 10m Hara et al. 2001
Synchrotron Inverse Compton scattering (estimated)
Cosmic rayIndex=2.7
Energy dependence of Energy dependence of Alpha distributionAlpha distribution
Signal <15 Normalize >30
Energy < 1 TeV 1 - 2 TeV 2 TeV -
424 ±98 events 4.3
117±73 events 1.6
-72±12 events 0.6