tevγ 線天文学の現状と将来
DESCRIPTION
TeVγ 線天文学の現状と将来. 森 正樹 東京大学宇宙線研究所. 「高エネルギー宇宙物理学の現状と将来」 2000 年 9 月 29-30 日 大阪大学. Cherenkov telescope. Cherenkov light from gamma-ray showers Lateral distribution & Timing distribution. Konopelko, TMACD-V, 1999. Imaging Cherenkov technique. γ. p. - PowerPoint PPT PresentationTRANSCRIPT
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TeVγ 線天文学の現状と将来
森 正樹東京大学宇宙線研究所
「高エネルギー宇宙物理学の現状と将来」 2000 年 9 月 29-30 日 大阪大学
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Cherenkov telescopeCherenkov light from gamma-ray showers
Lateral distribution & Timing distribution
Konopelko, TMACD-V, 1999
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Imaging Cherenkov technique
γ p
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Satellite vs Ground-based gamma-ray telescope
Base Satellite Ground
Gamma-raydetection
Direct(pair creation)
Indirect(atmosphericCherenkov)
Energy < 30 GeV(→ 100 GeV)
>300 GeV(→ 50 GeV)
Pros High S/NLarge FOV
Large areaGood ⊿θ
Cons Small areaHigh cost
Low S/N (CR bkgd.)(but imaging overcomes this!)
Small FOV
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Cherenkov telescopes in the world
( 終了 )
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TeV gamma-ray source catalog分類 天体名 グループ 備考
Grade A
(>5σ,multiple)
Crab
PSR1706-44
Mrk421
Mrk501
多数CANGAROO, Durham
多数多数
Plerion
Plerion
AGN (BL Lac)
AGN (BL Lac)
Grade B
(>5σ)
SN1006
Vela
RXJ1713.7-3946
PKS2155-304
1ES1959+650
BL Lac
CANGAROO
CANGAROO
CANGAROO
Durham
Utah7TA
Crimea
SNR
Plerion
SNR
AGN (BL Lac)
AGN (BL Lac)
AGN (BL Lac)
Grade C
(strong but with somequalifications)
Cas A
Cen X-3
1ES2344+514
3C66A
Geminga
B1509-58
HEGRA CT
Durham
Whipple
Crimea
Crimea
CANGAROO
SNR
X-ray binary
AGN (BL Lac)
AGN
Pulsar
Plerion
T.C. Weekes, Heidelberg WS, 2000
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TeV gamma-ray sky
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GeV gamma-ray skyThird EGRET catalog
E > 100 MeV
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Crab nebula Unpulsed spectrum Aharonian & Atoyan, astro-ph/9803091 /
Heidelberg WS, 2000
synchrotron
IC
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Crab pulsar spectrum: where is the cutoff?
Musquere, 26th ICRC, 1999
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Supernova remnant: SN1006
T. Naito
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SNR: SN1006 - interpretation Synch+IC Only IC? No pro-
tons?
Naito et al. Astron. Nach. 320, 1999
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Supernova remnant: Cas AGoret et al. 26th ICRC OG2.2.18, 1999
●HEGRA 2000
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Supernova remnant: RXJ1713RXJ1713.7-3946“SN1006 Jr.”
Muraishi et al., A&Ap 354, 2000
Tomida, Ph.D., 1999
CANGAROO
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AGN: Mrk 421 Rapid variability:
Faster at TeV?
Maraschi et al. ApJL 526, 1999(April 1998)
Whipple
BeppoSAX
BeppoSAX
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AGN: Mrk 421 spectrum Synchrotron
+ inverse Comptonmodel
Takahashi et al. astro-ph/0008505
One-zone SSC model
δ=14, B=0.14G
synchrotron
inverse compton
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AGN: TeV gamma-ray absorption by IR background
Protheroe et al. astro-ph/0005349
IR BackgroundMean free path for e+e- pair production
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AGN: Mrk 501 spectrum
Protheroe et al. astro-ph/0005349
Aharonian et al. A&Ap 349, 1999
Crisis?↓
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Next generation projects
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H.E.S.S.(High Energy Stereoscopic System)
23o16'18'' S 16o30'00'' E 1800 m a.s.l.
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H.E.S.S. telescope 16 (4 init.) telescopes
(120m spacing) Davies-Cotton design,
F/0.8 (f=15m), 108m2 mirror area(382 x 60cm)
Camera:960 x 29mm (0.16°) PMTs, 5° FOV, 600kg
Readout: 1GHz FADC Total 52 ton each
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VERITASMt. Hopkins, AZ(Montosa canyon
or north site)
(Very Energetic Radiation Imaging Telescope Array System)
23o N 111o W >2000 m a.s.l.
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VERITAS telescope 7 telescopes (80m spacin
g) Reflector: Davies-Cotton
design, D=10m (78.6m2), f=12m, 244x 60cm hexagonal mirrors (glass)
Camera: 499x 1” PMTs (0.15o spacing), 3.5o FOV
Readout: 500MHz FADC?
(This is the present 10m telescope: new design not available!)
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MAGIC(Major Atmospheric Gamma-ray Imaging Cherenkov Telescope)
La Palma,
Canary Island28.75o N 17.
89o W 2200 m a.s.l.
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MAGIC telescope Reflector: parabolic, D=1
7m (234m2), f=17m, 976x (50x50cm2) Al mirrors
Camera: [classical] 397x 1” PMTs (0.10o )+ 126x 1.5” PMTs (0.20o), 3.5o FOV, ~100kg [standard] HPDs (center) + PMTs
First Light in Summer 2001 (June 21, 2001)
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CANGAROO-III
Woomera, South Australia
31o06' S 136o
47' E 160 m a.s.l.
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CANGAROO-III telescope 4 telescopes (100m spacing) Parabola reflector consisting
of 114 mirrors of 80cmφ(57m2), f=8m, F/0.8
Camera: 4 FOV, 427x 3/4”PMTs (0.16, Hamamatsu R3478UV, TTS 0.36ns)
Readout: q-ADC & TDC
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Sensitivity of Cherenkov telescopes
VERITAS, ICRC1999
Major backgrounds:
p: CR proton
e: CR electron
: CR muon
NSB: night sky background
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Expected sensitivity
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Monitoring the gamma-ray sky
⇒ ?
⇒ ?
⇒ ?
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Future trends Lowering energy threshold (→5 GeV)
Larger light collectorHigher altitude
Increasing FOV (→1 sr)“All-sky” TeV gamma-ray monitor
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High altitude Cherenkov telescope
High altitude→higher photon density→lower energy→high statistics/ overlapping to satellites
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Cherenkov light density at high altitude
Aharonian et al. astro-ph/0006163
γ p
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Sensitivity of 4×50m2 telescope array at 5km a.s.l. (e.g. Atacama)
Aharonian et al. astro-ph/0006163
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All-sky TeV gamma-ray monitor 5 mφ, 1 sr telescope, 1 TeV threshold
・ CR rate (>1 TeV): 8 ・ 10-6cm-2s-1 × 3 ・ 108cm2 = 3 kHz・ Muons (>1 GeV): 7 ・ 10-3cm-1s-1 × 2 ・ 105cm2 = 1.4 kHz・ High threshold to reduce N.S.B.・ 0.1o resolution camera (many channels…)・ Stereo if necessary・ Good monitor for GRBs
Not far away from the present technology!Kifune and Takahashi, TMACD-IV, 1997
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All-sky monitor optics EUSO/OWL type large FOV optics
EUSO proposal, 2000
↑ □ movable camera? ↓
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Science to come Plerions (pulsar nebula)
Inverse Compton? ← synchrotron origin? Pulsars
Cutoff in pulse component? ← polar cap/outer gap SNRs
π0 contribution? ← cosmic ray origin AGNs
Gamma-ray source: e± or p?Intergalactic IR ← cosmology
EGRET unIDs, Neutralinos, GRBs, QG,Diffuse gamma,…, and more?
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Gamma-rays and cosmic-rays
T. Kifune, 2000