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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