Gus Sinnis CTA Workshop, Paris, March 2007 Synoptic TeV Telescopes: Recent Results & Future Plans...
-
Upload
madlyn-grant -
Category
Documents
-
view
218 -
download
2
Transcript of Gus Sinnis CTA Workshop, Paris, March 2007 Synoptic TeV Telescopes: Recent Results & Future Plans...
Gus SinnisCTA Workshop, Paris, March 2007
Synoptic TeV Telescopes:Recent Results & Future Plans
Gus Sinnis
Los Alamos National Laboratory
Gus SinnisCTA Workshop, Paris, March 2007
Detectors in Gamma-Ray AstrophysicsHigh Sensitivity
HESS, MAGIC, CANGAROO, VERITAS
Large Aperture/High Duty Cycle
Milagro, Tibet, ARGO, HAWC
Low Energy Threshold
EGRET/GLAST
Energy Range .05-50 TeVArea > 104 m2
Background Rejection > 99%Angular Resolution 0.05o
Aperture 0.003 srDuty Cycle 10%
Energy Range 0.1-100 GeVArea: 1 m2
Background FreeAngular Resolution 0.1o - 0.3o
Aperture 2.4 srDuty Cycle > 90%
Energy Range 0.1-100 TeVArea > 104 m2
Background Rejection > 95%Angular Resolution 0.3o - 0.7o
Aperture > 2 srDuty Cycle > 90%
High Resolution Energy SpectraStudies of known sourcesSurveys of limited regions of sky
Unbiased Sky Survey (<100 GeV)Extended SourcesTransients (AGN, GRBs) <100 GeVSimultaneous Observations
Unbiased Sky Survey Extended SourcesTransients (GRB’s) Simultaneous Observations
Gus SinnisCTA Workshop, Paris, March 2007
The Tibet Air Shower Array
• 4300m asl• Scintillator array• 497 detectors
– 0.5m2 each– 5mm lead on each
• 5.3x104 m2 (phys. area)• 3 TeV median energy• 680 Hz trigger rate• 0.9o resolution
Gus SinnisCTA Workshop, Paris, March 2007
8 meters
e
80 meters
50 meters
10 m
• 2600m asl• Water Cherenkov Detector• 898 detectors
– 450(t)/273(b) in pond– 175 water tanks
• 4000 m2/3.4x104 m2 (phys. area)• 2-12 TeV median energy• 1700 Hz trigger rate• 0.3o-0.5o resolution• 99% background rejection
Milagro
Gus SinnisCTA Workshop, Paris, March 2007
Background Rejection in Milagro
Proton MC Proton MC
Data Data MC MC
Hadronic showers contain penetrating component: ’s & hadrons
– Cosmic-ray showers lead to clumpier bottom layer hit distributions– Gamma-ray showers give smooth hit distributions
Gus SinnisCTA Workshop, Paris, March 2007
Background Rejection (Cont’d)
( )mxPE
nFitfOut+fTop=A
∗4
mxPE: maximum # PEs in bottom layer PMT
fTop: fraction of hit PMTs in Top layer
fOut: fraction of hit PMTs in Outriggers
nFit: # PMTs used in the angle reconstruction
New Rejection Parameter: A4New Rejection Parameter: A4
Apply a cut on A4 to reject hadrons:A4 > 3 rejects 99% of Hadrons
retains 18% of Gammas
S/B increases with increasing A4
Gus SinnisCTA Workshop, Paris, March 2007
Analysis Example: The Crab Nebula
Weight each eventby Expected S/B
Excess Signal = 2,074Background = 60,637S/B = 3.4%
Excess Signal = 44Background = 74S/B = 60%
A4 > 3.0
A4 > 12.0
Gus SinnisCTA Workshop, Paris, March 2007
Cosmic-Ray Anisotropy: Tibet Array
4.0 TeV
6.2 TeV
12 TeV
50 TeV
300 TeV
From Science, V314, pp.439 – 443 (2006), by the analysis method (I)
(slide from C.T. Yan, Texas in Australia)
Excess from the Cygnus regionExcess from the Cygnus region Energy dependence to anisotropyAnisotropy fade away ~ 300 TeV
(Statistics?)
Gus SinnisCTA Workshop, Paris, March 2007
Milagro Sky Survey
Cygnus region shows two new TeV gamma-ray sources Diffuse emission from Cygnus region: ~ 2 x Fcrab (120 square degrees) l (65,85), b (-3,3) A new TeV source at low declinations
Gus SinnisCTA Workshop, Paris, March 2007
Galactic Longitude Flux Profile
• Flux calculations assume a Crab spectrum (-2.62)• 3 sources detected, MGRO J1909+06, 1MGRO J2019+37, and
MGRO J2033+42
1 Abdo et al., arXiv:astro-ph/0611691, to appear ApJ Letters
MGRO J2019+37
Cygnus Region
GALPROP optimized to fit EGRET
Longitude Profile |b|<2°
below horizon
MGRO J1909+06
MGRO J2033+42
Gus SinnisCTA Workshop, Paris, March 2007
Diffuse Emission from Cygnus Region
• Exclude an area of 3x3 degree square bin around MGRO J2019+37
• Strong & Moskalenko optimized model– Fit to EGRET– Increase 0 and IC component
throughout Galaxy– Milagro flux ~2.5x prediction– Hard spectrum cosmic ray
sources?– Unresolved point sources?
Strong & Moskalenko
GALPROP model of Cygnus Region
standard
optimized
Inverse Compton
Pion
bremsstrahlung
Gus SinnisCTA Workshop, Paris, March 2007
MGRO J2019+37MGRO J2019+37
Statistical Sig. 11.3 σ Coincident with 2 EGRET
sources (unidentified)3EG J2016+36573EG J2021+3716 (PWN G75.2+0.1?)
Flux @ 12 TeV ~500 mCrab Width = 0.32o ± 0.12o
Location:l = 75.1o ± 0.1o
stat ± 0.3osys
b = 0.3o ± 0.1ostat ± 0.3o
sys
MGRO J2019+37
Gus SinnisCTA Workshop, Paris, March 2007
MGRO J2033+42
Will put in Galactic coordinates and change color scale
Prelim
inary
MGRO J2033+42
MGRO J2033+42 Statistical Sig. 7.1 σ Coincident with:
HEGRA TeV J2032+4130 EGRET 3EG J2033+4118
Flux @ 12 TeV ~ 350 mCrab Location:
l = 80.4o ± 0.4ostat ± 0.3o
sys
b = 1.0o ± 0.3ostat ± 0.3o
sys
Gus SinnisCTA Workshop, Paris, March 2007
MGRO J1909+06
MGRO J1909+06 Statistical Sig. 8.2 σ Flux @ 12 TeV ~850 mCrab Location:
l = 40.5o ± 0.1ostat ± 0.3o
sys
b = -1.0o ± 0.1ostat ± 0.3o
sys
Will put in Galactic coordinates and change color scale
Prelim
inary
Gus SinnisCTA Workshop, Paris, March 2007
Galactic Plane Survey Summary
• MGRO J2019+37 is coincident with 3EG J2016+3657 and 3EG J2021+3716• MGRO J2033+42 is coincident with TeV 2032+4130 (dN/dE = (0.5±0.2)x10-14
/TeV/cm2/s) and 3EG J2033+4118
2.4±0.4stat11.3 75.1±0.1stat , 0.3±0.1statMGRO J2019+37
4.8±0.5stat15.2-175.4±0.1stat , -5.7±0.1statCrab
1.0±0.4stat4.5106.4±0.5stat , 1.7±0.8stat
34.1±0.3stat , 0.0±0.2stat
77.2±0.2stat , -4.0±0.2stat
76.3±0.1stat , -1.9±0.2stat
80.4±0.4stat , 1.0±0.3stat
40.5±0.1stat , -1.0±0.1stat
1Position (l, b)
1.2±0.2stat5.6
0.9±0.2stat5.8
5.5±1.4stat5.1
1.7±0.4stat7.1MGRO J2033+42
4.1±0.9stat8.2MGRO J1909+06
Flux (x10-14)
(/TeV/cm2/s)
Significance
(pre-trials)Object
2 30% systematic error on flux1 0.3° systematic error on position
>5σ
p ost
-tr i
als
Gus SinnisCTA Workshop, Paris, March 2007
Future Synoptic TeV Telescopes
ARGOComplete summer 2007Chinese-Italian collaboration4300m asl (YBJ, Tibet)RPC carpet10-15σ /√year on Crab
Tibet w/Muon DetectorsProposal submittedChina-Japan collaboration4300m asl (YBJ, Tibet)Tibet w/buried water tanksEmphasis 10-1000 TeV
HAWCProposal submitted>4100m asl (Tibet or Mexico)Water Cherenkov100 σ /√year on Crab
Gus SinnisCTA Workshop, Paris, March 2007
ARGO
ScheduleEnd summer 2006 154 Cluster mounted Start data taking w/out Pb
Early 2007 Install Pb
Summer 2007 Fully operational with Pb + AnalogRO
Central carpet (130 clusters/5800 m2) in DAQ No Pb installed 24 Cluster with AnalogRO
Gus SinnisCTA Workshop, Paris, March 2007
Tibet w/Muon Detector
Future AS+MD Array (Type 2)
7.2m x 7.2m x 1.5m depth Water pool20”PMT x 2 (HAMAMATSU R3600)Underground 2.5m ( ~515g/cm2~19X0)
Material:Concrete poolWhite epoxy resin paint184 detectorsTotal muon area 9540 m2
Gus SinnisCTA Workshop, Paris, March 2007
Tibet MD: Sensitivity10 TeV:Cut value NPE=~40Background: ~99% RejectionGamma rays: ~60% SurvivalSensitivity: ~6 times Improved
100 TeV:Cut value NPE=~600Background: >99.8% RejectionGamma rays: ~100% SurvivalSensitivity: >20 times Improved Almost background free!
1000 TeV:Cut value NPE=~8000Background: >>99.8% RejectionGamma rays: ~100% SurvivalSensitivity: Background free!
Gus SinnisCTA Workshop, Paris, March 2007
High Altitude Water Cherenkov Telescope
HAWC
A proposal to redeploy the Milagro PMTs
In a Large Reservoir (22,500 m2)
at Higher Altitude
10-15 times more sensitive than Milagro
Gus SinnisCTA Workshop, Paris, March 2007
Detector Layout
Milagro:450 PMT (25x18) shallow (1.4m) layer273 PMT (19x13) deep (5.5m) layer175 PMT outriggers
Instrumented Area: ~40,000m2
PMT spacing: 2.8mTotal Area: 3500m2
det Area: 2200m2
HAWC:900 PMTs (30x30)5.0m spacingSingle layer with 4m depth
Instrumented Area: 22,500m2
PMT spacing: 5.0mTotal Area: 22,500m2
det Area: 22,500m2
HAWCMilagro
Gus SinnisCTA Workshop, Paris, March 2007
Gamma/Hadron Separation
Circles are EM particles > 1 GeV Circles are ’s & hadrons > 1 GeVCircles are 30m radius (~area of Milagro layer)
prot
ons
gam
mas
nHit/cxPE>5.0Eff = 34%Eff CR = 3%
nHit/cxPE>5.0Eff = 56%Eff CR = 1.5%
Gus SinnisCTA Workshop, Paris, March 2007
Sensitivity of Synoptic TeV Telescopes
Tibet
Milagro
HAWC
sHAWC
TibetMD
Whipple
ARGO
Crab
HESS/VERITAS
GLAST
Gus SinnisCTA Workshop, Paris, March 2007
• Enormous progress has been made in the past decade in TeV survey technology– Measurement of cosmic-ray anisotropy– Discovery of diffuse TeV gamma rays from the Galactic plane – Discovery of diffuse TeV gamma rays from the Cygnus region– Discovery of a new extended TeV source in the Cygnus region– Discovery of at least 2 additional sources in the Galactic plane
• HAWC can attain high sensitivity over an entire hemisphere– ~15 times the sensitivity of Milagro– ~5 sigma/√day on the Crab– 30 mCrab sensitivity over hemisphere– Unsurpassed sensitivity to extended sources– Unique TeV transient detector
• (5x Crab in 10 minutes!)– Can be built quickly @ low cost
Conclusion