gus sinnis cta workshop, paris, march 2007 synoptic tev telescopes: recent results & future...

Gus SinnisCTA Workshop, Paris, March 2007

Synoptic TeV Telescopes:Recent Results & Future Plans

Gus Sinnis

Los Alamos National Laboratory


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


Current Generation EAS ArraysT

ibet

III

Mila

gro


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


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


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


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


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


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?)


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


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


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


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


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


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


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


The Multi-Wavelength Sky

TeV gamma rayHESS

Milagro


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


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


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


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!


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


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


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%


Sensitivity vs. Source Size


HAWC Sky Survey


Sensitivity of Synoptic TeV Telescopes

Tibet

Milagro

HAWC

sHAWC

TibetMD

Whipple

ARGO

Crab

HESS/VERITAS

GLAST


• 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

gus sinnis cta workshop, paris, march 2007 synoptic tev telescopes: recent results & future...

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