CTACTAThe next generation ultimate The next generation ultimate

gamma ray observatorygamma ray observatory

M. TeshimaM. Teshima

Max-Planck-Institute for PhysicsMax-Planck-Institute for Physics

CTA

SNRsSNRs Cold Dark MatterCold Dark MatterGRBsGRBs

Cosmological Cosmological -Ray Horizon-Ray Horizon

Physics ObjectivesPhysics Objectives

Origin of Origin of Cosmic Cosmic RaysRays

Quantum GravityQuantum Gravity

PulsarsPulsars AGNsAGNs

CTA Galactic SourcesGalactic Sources

HESS Galactic plane Survey

Survey in 2-3% Crab unit

Astro-ph/051039717 sources + Several

PWNsShell type SNRsX-Ray BinaryUn-ID sources

CTA Extragalactic sourcesExtragalactic sources

Source Redshift Spectral Index Type FirstDetection

Confimation

M87 0.004 2.9 FR I HEGRA HESS

Mkn 421 0.031 2.2 BL Lac Whipple Many

Mkn 501 0.034 2.4 BL Lac Whipple Many

1ES 2344+514 0.044 2.9 BL Lac Whipple HEGRA,MAGIC1ES 1959+650 0.047 2.4 BL Lac Tel. Array Many

PKS 2005-489 0.071 4.0 BL Lac HESS

PKS 2155-304 0.116 3.3 BL Lac Mark VI HESS

H1426+428 0.129 3.3 BL Lac Whipple Many

H2356-309 0.165 3.1 BL Lac HESS

1ES 1218+304 0.182 3.0 BL Lac MAGIC

1ES 1101-232 0.186 2.9 BL Lac HESS

PG 1553 >0.25 4.0 BL Lac HESS MAGIC

BL Lac objects

1.5

2.0

2.5

3.0

3.5

4.0

4.5

0 0.1 0.2 0.3 0.4

Redshift Parameter z

Spe

ctra

l Ind

ex

PKS2005 PG1553

New Sources

Spectral Indices of new sources range 3~4

CTAPG 1553PG 1553(z>0.25)(z>0.25)

Very Soft energy spectrumthe attenuation　 by pair creation

X-Ray Intensity =6.5μ JyMrk421 9.9 μJyMrk501 9.4 μJy

CTA Absorption of Absorption of gamma rays in the universegamma rays in the universe

Pair Creation; γ＋ γ e+ + e-

CTA The SSC frameworkThe SSC framework

Fossati et al. 1998

Higher Z Higher source luminosity Lower IC peak softer spectrum

X-ray intensity at 1keVPG 1553 6.5 μJy z~0.3Mrk421 9.9 μJy z=0.03Mrk501 9.4 μJy z=0.03PG1553’s source luminosity ~100 x Mrk

BL Lac objects

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

0.50 1.00 1.50 2.00 2.50 3.00Log (X- ray source Luminosity)

Spe

ctra

l Ind

ex

2005 1553

2344

CTA From HESS & MAGIC to CTAFrom HESS & MAGIC to CTA

About 30 sources are now identified as VHE gamma souAbout 30 sources are now identified as VHE gamma sources.rces.

GLAST will see ~3000 of GeV sources around 2010GLAST will see ~3000 of GeV sources around 2010 Our target in VHE EnergyOur target in VHE Energy

~100 VHE sources in 2010 by HESS-II and MAGIC-II~100 VHE sources in 2010 by HESS-II and MAGIC-II~1000 VHE sources in 2020 by CTA~1000 VHE sources in 2020 by CTA

CTA Sensitivity must be 10 times better than HESS, and MAGICCTA Sensitivity must be 10 times better than HESS, and MAGIC

Importance of all sky observatory Importance of all sky observatory full sky survey full sky survey rel relatively large FOV is favoredatively large FOV is favored

Extend HESS galactic plane survey to entire skyExtend HESS galactic plane survey to entire sky

CTA By W.Hofmann

∝Ntel

∝Area50hrs

Background Limited Signal Limited

CTA Kifune’s Plot Kifune’s Plot (my optimistic expectation)(my optimistic expectation)

~3000 sourcesby GLAST, AGILE

~1000 sourcesby CTA

GLASTAGILE

CTA VHE Log(S)-Log(N) plotVHE Log(S)-Log(N) plot

0

0.5

1

1.5

2

2.5

0 1 2 3 4

Log (Intensity)

Log

(N

umbe

r)

HESS

MAGIC

HESS-I ~30 sourcesMAGIC-I ~20 sources

Log(N) ~ -1.0 Log(S) ???

HESS-II ~60 sourcesMAGIC-II ~40 sources

CTA South ~300 sourcesCTA North ~200 sources

HESS-IIMAGIC-II

CTA

CTA

Picture: Courtesy of W.Hofmann

Option:Mix of telescope types

~10 central huge telescopes

~100 small telescopes outside

CTAStrategy in Low EnergyStrategy in Low Energy

~10GeV Eth~10GeV EthImage quality is limited by the number of photons and air shower fluImage quality is limited by the number of photons and air shower fluctuationsctuationsIncrease photo-collection efficiencyIncrease photo-collection efficiency

Increase telescope density (gain x 4)Increase telescope density (gain x 4)~100m spacing ~100m spacing ~50m spacing ~50m spacingMany sampling points Many sampling points reduce shower fluctuation effect reduce shower fluctuation effect

Increase telescope diameter (gain x 3)Increase telescope diameter (gain x 3)12m-17m φ12m-17m φ 20-30m φ 20-30m φ

Increase Q.E. of photo-detectors (gain x 3)Increase Q.E. of photo-detectors (gain x 3)Q.E. 20% Q.E. 20% 60-80% 60-80%

Timing between telescopes may help Timing between telescopes may help S. Biller S. Biller

Total gain 30~40 in photo collection efficiency could be realisticTotal gain 30~40 in photo collection efficiency could be realistic 10GeV threshold energy with reasonable sensitivity10GeV threshold energy with reasonable sensitivity

Photon sampling rate: HESS, MAGIC ~ 1/1000Photon sampling rate: HESS, MAGIC ~ 1/1000Photon sampling rate in CTA should be ~1/30 Photon sampling rate in CTA should be ~1/30 (10% mirror area, 50% Q.E.)(10% mirror area, 50% Q.E.)Significant improvement in data quality Significant improvement in data quality intensive M.C. is necessa intensive M.C. is necessaryry

CTAStrategy in High energyStrategy in High energy

up to 100TeVup to 100TeV

Extension of the sensitivity up to 100TeV tExtension of the sensitivity up to 100TeV to study galactic cosmic ray source o study galactic cosmic ray source CTA CTA south onlysouth only

Current IACTs’ sensitivity is just limited by Current IACTs’ sensitivity is just limited by the number of gamma eventsthe number of gamma events Emax ~10TeV Emax ~10TeV Emax ~100TeV Emax ~100TeV ~10~105 5 mm2 2 (300m x 300m)(300m x 300m) ~10 ~107 7 mm2 2 (3km x 3km)(3km x 3km)

CTA Multi-Messengers observationMulti-Messengers observationAll sky observatory (N,S stations)All sky observatory (N,S stations)

Gamma Rays

Neutrinos

Gamma Ray &X-Ray Satellites

IceCube: 2010 Completion of the construction

CTA North

CTA South

CTAHESS-II and MAGIC-II can be gooHESS-II and MAGIC-II can be goo

d R&Ds for CTAd R&Ds for CTA

HESS-II28m diameter telescopeLower threshold energyIn 2008

MAGIC-II2x17m, High Q.E. detectorsLower threshold energyHigh PrecisionIn 2007

March 2006

CTA SummarySummary

We definitely need CTA for the development of VHE astrophysics afWe definitely need CTA for the development of VHE astrophysics after HESS-II and MAGIC-IIter HESS-II and MAGIC-II

500~1000 sources will be observed in 10-20 years operation 500~1000 sources will be observed in 10-20 years operation 10- 10-20 hrs/source (time limited)20 hrs/source (time limited)

CTA could be an ultimate ground based gamma ray observatory anCTA could be an ultimate ground based gamma ray observatory and we should consider north & south stations (All sky observatory)d we should consider north & south stations (All sky observatory)

The number of galactic sources may be limitedThe number of galactic sources may be limited

Multi-wavelength and multi-messenger observation are very importaMulti-wavelength and multi-messenger observation are very important to understand the nature of high energy sourcesnt to understand the nature of high energy sources

New advanced photon detector development will have a strong impNew advanced photon detector development will have a strong impact in the design of CTA (HPD, SiPM)act in the design of CTA (HPD, SiPM)