CTA CTA The next generation ultimate The next generation ultimate gamma ray observatory gamma ray observatory M. Teshima M. Teshima Max-Planck-Institute for Max-Planck-Institute for Physics Physics
Jan 18, 2016
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)