1. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Synoptic TeV Telescopes Results from Milagro Plans for HAWC

2. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Milagro 8 meters e  80 meters 50 meters A Water Cherenkov detector. Reconstruct shower direction to 0.3-0.7 o from the timing shower front. Reject background by detecting penetrating component of hadronic showers Field of view is ~2 sr Duty factor ~95% Trigger rate ~1700 Hz (6 Mbytes/sec) Milagro Cross Section Schematic

3. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Milagro with Outriggers 175 Outrigger tanks (Tyvek lined – water filled) 2.4m diameter, 1m deep 34,000 m 2 enclosed area Completed in May 2003

4. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Background Rejection in Milagro Proton MC Data  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

5. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Parameterize “clumpiness” of the bottom layer hits –Compactness Require C > 2.5 50% gammas & 10% hadrons Sensitivity improved by 1.6 Require A 4 > 3.0 20% gammas & 1% hadrons Sensitivity further improved by 1.4 Background Rejection (Cont’d) mxPE:maximum # PEs in bottom layer PMT nb2:# bottom layer PMTs with 2 PEs or more fTop:# fraction of hit PMTs in Top layer fOut:# fraction of hit PMTs in Outriggers nFit:# PMTs used in the angle reconstruction

6. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Spectral Determination A4 is related to energy 2-20 TeV useful range Parameterization of events

7. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Crab Spectrum Exponential cut off energy is E c = 31.0 TeV (w/large error bars) Preliminary

8. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Milagro Sky Survey Crab Nebula Cygnus Region MRK 421 2003 (pre-outrigger) 2006 (post-outrigger)

9. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Significance GP diffuse excess clearly visible from l=25° to l=90° Cygnus Region shows extended excess F Cygnus ~ 2 x F crab 120 square degrees l (65,85), b (-3,3) The Galactic Plane

10. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis The Cygnus Region  Contours are GALPROP pion model  Crosses are EGRET (unidentified) sources  TeV/matter correlation good Chance noncorrelation 1.5x10 -6  Brightest TeV Region –MGRO J2019+37 –~0.5 Crab @ 12 TeV –Extent = 0.32 ± 0.12 deg. –Coincident with 2 EGRET sources (unID) PWN G75.2 + 0.1 Blazar (B2013+370) –Energy Analysis in progress Flux @ 12.5 TeV= E 2 dN/dE = (4.18 ± 0.52 stat ± 1.26 sys ) x 10 -10 TeV cm -2 s -1 sr -1 (excluding new source & assuming E -2.6 ) ~3.5 Crab in 180 sq. degree region

11. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Cygnus Region: Diffuse Gamma Rays Strong & Moskalenko GALPROP model of Cygnus Region Strong & Moskalenko optimized model –Increase  0 and IC component throughout Galaxy –Milagro 2-6x above prediction (optimized- standard models) –Unresolved sources? –Cosmic-ray accelerators? standard optimized Inverse Compton Pion bremsstrahlung

12. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Cygnus Region: Multi-wavelength 0.1 GeV Milagro 10 TeV gamma-ray Radio Continuum (408MHz) Atomic Hydrogen Radio Continuum (2.5GHz) Molecular Hydrogen X-Ray Gamma-Ray (100 MeV) Gamma-Ray (10 TeV) Radio Continuum (408MHz) Atomic Hydrogen Radio Continuum (2.5GHz) Molecular Hydrogen X-Ray Gamma-Ray (100 MeV) Gamma-Ray (10 TeV)

13. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis High Altitude Water Cherenkov Telescope  HAWC A proposal to redeploy the Milagro PMTs with Wider Spacing at Higher Altitude 10-15 times more sensitive than Milagro

14. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis HAWC Goals Complete hemisphere survey to 25 mCrab –After 4 years Detailed map of Galactic diffuse emission Search for extended sources Detect AGN transients –4 Crab in 15 minutes Detect GRBs to 1/100 keV fluence Spectra to the highest energies (~100 TeV) Contemporaneous with GLAST, HESS, VERITAS, & IceCube

15. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Altitude Effect 4100m 2600m Difference between 2600m (Milagro) and 4100m: ~ 6x number of particles ~ 2-3x lower median energy

16. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Detector Layout Milagro: 450 PMT (25x18) shallow (1.4m) layer 273 PMT (19x13) deep (5.5m) layer 175 PMT outriggers Instrumented Area: ~40,000m 2 PMT spacing: 2.8m Total Area:3500m 2  det Area:2200m 2 HAWC: 900 PMTs (30x30) 5.0m spacing Single layer with 4m depth Instrumented Area: 22,500m 2 PMT spacing: 5.0m Total Area:22,500m 2  det Area:22,500m 2 HAWC Milagro

17. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Detector Layout Milagro: 2 layers at depths 1.4m – “Air Shower” Layer 6.0m – “Muon” Layer HAWC: Single intermediate layer Opaque curtains between cells 4m 6 m 5 m 2.8 m 1.4 m

18. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Curtains HAWC single muon rate = ~1 MHz Install curtains to optically isolate the PMTs. Avoid triggering on single muons Intrinsic Gamma hadron separation

19. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis HAWC Trigger Rate Multiplicity trigger at ~80 PMTs gives same CR trigger rate as Milagro at 50 PMTs Much higher Gamma-ray rate. Milagro HAWC Gamma-Ray Rate

20. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis  = ~0.4 deg  = ~0.25 deg Angular Resolution nTrigger = 50PMTs nTrigger = 200 PMTs

21. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Gamma/Hadron Separation Gammas Protons 30 GeV70 GeV230 GeV 20 GeV70 GeV 270 GeV Size of HAWC Size of Milagro deep layer Energy Distribution at ground level

22. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Gamma/Hadron Separation Circles are EM particles > 1 GeV Circles are  ’s & hadrons > 1 GeV Circles are 30m radius (~area of Milagro bottom layer) protons gammas

23. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Gamma/Hadron Separation nHit/cxPE>5.0 Eff  = 34% Eff CR= 3% nHit/cxPE>5.0 Eff  = 56% Eff CR= 1.5% Q Factor (sig/√bg) Cuts soft hard HAWC 2.0 4.5 HESS 3.2 4.4 HESS   = 56% -> 28%  CR = 3% -> 0.4% (shape only)

24. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Effective Area Gamma Area:  5.0  <1.0 O 200 PMT Trigger 80 PMT Trigger 20 PMT Trigger Area of GLAST Detector Size

25. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis HAWC Point Source Sensitivity Q (sig/√bg) (HAWC/Milagro) = 15 Significance from Crab transit (4 hr)~5  Crab 1 year ~100  Energy Resolution~30% above median Angular Resolution0.25 O -0.5 O S/B (hard cuts) ~ 1:1 for Crab Single transit: 20 excess / 25 bkg HAWC HAWC II GLAST EGRET Crab Nebula Whipple VERITAS/ HESS Current synoptic instruments

26. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Sensitivity vs. Source Spectrum Milagro HESS HAWC

27. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Sensitivity vs. Source Size

28. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Sky Surveys

29. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis GRB Sensitivity Fluence Sensitivity to 10s GRB. Both Milagro and HAWC can “self trigger” and generate alerts in real time. GRB rate in FOV ~100 GRB/year (BATSE rate) MilagroHAWC

30. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Pond Design Fiducial volume: 150m x 150m x 4m Actual size: 170m x 170m x 6m 1:1 slope at perimeter 6 m depth to allow for 4m over PMTs. Total volume: 115 Ml 170m 150m 4.5-5.0 m 6m

31. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Building Construction Prefabricated steel building –Components manufactured at factory. –Shipped to site (~9 trucks) –Beams bolted not welded. –Cost ~1.5M$ (not installed) Building installation ~400 k Pond excavation ~300 k Liner cost ~600 k Total facility cost ~3.5 M Total Cost ~5.2 M 162m

32. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis YBJ Laboratory – Tibet, China Elevation: 4300m Latitude: 30 O 13’ N Longitude: 90 O 28’ E Lots of space. Available power. Available water. Tibet Air Shower Array

33. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Sierra Negra, Mexico 3 1 2 LMT 1 km N Elevation = 4100m or 4300m Latitude = 19 O 00’N Longitude = 97 O 17’ W

34. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis HAWC Status and Timeline A proposal for a total project cost ~$5M has been submitted by the US groups to NSF –A proposal will be sent to DoE –Mexican Collaborators have submitted a proposal to their funding agency A final site decision will be made this year If approved: –Next year we will do site specific design –Start construction in 2008 –Complete construction and start data taking in 2010

35. Los Alamos National Laboratory Adelaide, Australia. December 2006 Gus Sinnis Conclusion Milagro has made significant discoveries: –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 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 entire hemisphere –Unsurpassed sensitivity to extended sources –Unique TeV transient (AGN/GRB) detector –Can be built quickly @ low cost