1. Jordan Goodman HAWC Review - December 2007 HAWC A Wide-Field Gamma-Ray Telescope Jordan A. Goodman University of Maryland

2. Jordan Goodman HAWC Review - December 2007 Outline of Our Presentation Overview plus Milagro history (Jordan Goodman) (15min)Overview plus Milagro history (Jordan Goodman) (15min) Milagro Observations (Gus Sinnis) (30 min)Milagro Observations (Gus Sinnis) (30 min) HAWC Science (Brenda Dingus,Julie McEnery) (45 min)HAWC Science (Brenda Dingus,Julie McEnery) (45 min) HAWC Design & Performance (Andy Smith, Vlasios Vasileiou) (1hr)HAWC Design & Performance (Andy Smith, Vlasios Vasileiou) (1hr) HAWC Technical Engineering Design (Michael Schneider, Jim Linnemann, Andy Smith, John Matthews) (1hr)HAWC Technical Engineering Design (Michael Schneider, Jim Linnemann, Andy Smith, John Matthews) (1hr) Site & Mexican Collaboration (Alberto Carraminana) (30min)Site & Mexican Collaboration (Alberto Carraminana) (30min) Construction Plan, Management & Budget (Jordan Goodman) (45 min)Construction Plan, Management & Budget (Jordan Goodman) (45 min) Education/Outreach & Wrap Up- (Jordan Goodman) (15 min)Education/Outreach & Wrap Up- (Jordan Goodman) (15 min)

3. Jordan Goodman HAWC Review - December 2007 Why are we here? HAWC is an intermediate scale experiment (<$10M)HAWC is an intermediate scale experiment (<$10M) With the passing of SAGENAP there is no standing committee with the expertise to review proposals of this scaleWith the passing of SAGENAP there is no standing committee with the expertise to review proposals of this scale It is too big (and complex) to be handled by standard mail-in reviewsIt is too big (and complex) to be handled by standard mail-in reviews If experiments like this are to funded they need to come to the January NSF PA panel with a strong recommendation from experts who can say:If experiments like this are to funded they need to come to the January NSF PA panel with a strong recommendation from experts who can say: –That there is a compelling science case –That it is technically feasible –That the cost estimate is reasonable

4. Jordan Goodman HAWC Review - December 2007 University Grant Program Report (approved by HEPAP) The Scientific Advisory Groups (SAGs) should regularize their role in reviewing projectsThe Scientific Advisory Groups (SAGs) should regularize their role in reviewing projects – Each SAG should actively monitor and prioritize the experiments and R&D in its area. It should evaluate both physics goals and technical design. –The SAGs should report to P5, timing their reports so that they are available to P5 when needed. –The SAGs should review all experiments with expected construction costs above $5M, along with smaller ones seeking review. This includes both experiments that are affiliated with a U.S. laboratory and those that are not. Additional SAGs should be created as needed to cover all areas (taking care to avoid proliferation). –HEPAP should establish mechanisms for prioritizing experiments whose cost is above $5M but below the P5 threshold. The prioritization process should take advantage of input from the SAGs and should reflect the breadth of the field.

5. Jordan Goodman HAWC Review - December 2007 Milagro We proposed Milagro in 1990We proposed Milagro in 1990 –~$3M in an existing pond –With outriggers

6. Jordan Goodman HAWC Review - December 2007 Milagro We proposed Milagro in 1990We proposed Milagro in 1990 –~$3M in an existing pond –With outriggers It was before EGRET & BATSEIt was before EGRET & BATSE –The Crab was the only confirmed source 1990

7. Jordan Goodman HAWC Review - December 2007 Milagro We proposed Milagro in 1990We proposed Milagro in 1990 –~$3M in an existing pond –With outriggers It was before EGRET & BATSEIt was before EGRET & BATSE –The Crab was the only confirmed source We expected to get 0.5 o angular resolution and 5  /yr on the CrabWe expected to get 0.5 o angular resolution and 5  /yr on the Crab From Proposal

8. Jordan Goodman HAWC Review - December 2007 Milagro We proposed Milagro in 1990We proposed Milagro in 1990 –~$3M in an existing pond –With outriggers It was before EGRET & BATSEIt was before EGRET & BATSE –The Crab was the only confirmed source We expected to get 0.5 o angular resolution and 5  /yr on the CrabWe expected to get 0.5 o angular resolution and 5  /yr on the Crab We built Milagro on budget even though the funding was stretched out over 10 yearsWe built Milagro on budget even though the funding was stretched out over 10 years Current Performance on the Crab ~9  /yr with  /h separation and weighting ~4  /yr without  /h separation and weighting Pre-outrigger Ang res = 0.70° Post-outrigger Ang res = 0.41°

9. Jordan Goodman HAWC Review - December 2007 Milagro Milagro was the first water-Cherenkov EAS detectorMilagro was the first water-Cherenkov EAS detector We developed the technique for reconstruction and background rejectionWe developed the technique for reconstruction and background rejection Using this first generation detector we:Using this first generation detector we: –surveyed the Northern Sky at TeV energies –made the first detection of diffuse emission from the galactic plane –found 4 new galactic TeV sources –observed the highest energy gamma rays every seen (in excess of 100 TeV) –mapped diffuse emission of the Cygnus Region TeV gamma ray HESS Milagro

10. Jordan Goodman HAWC Review - December 2007 TeV  Rays: New Window on the Sky TeV gamma ray HESS Milagro

11. Jordan Goodman HAWC Review - December 2007 TeV  Rays: New Window for the Sky TeV gamma ray HESS Milagro

12. Jordan Goodman HAWC Review - December 2007 What we learned from Milagro The pond had the sensitivity we expectedThe pond had the sensitivity we expected We could reconstruct shower directions to within ~0.4 o with a single layer detector.We could reconstruct shower directions to within ~0.4 o with a single layer detector. That you could use the deep layer to reject background proton showers with high efficiencyThat you could use the deep layer to reject background proton showers with high efficiency That gamma showers that hit the pond could be well reconstructed, but were often rejected as protons, so we needed outriggers to reconstruct gammas that were off the pondThat gamma showers that hit the pond could be well reconstructed, but were often rejected as protons, so we needed outriggers to reconstruct gammas that were off the pond That you could operate a detector remotely with 95% on timeThat you could operate a detector remotely with 95% on time

13. Jordan Goodman HAWC Review - December 2007 What would make Milagro better? Being higher up in the atmosphereBeing higher up in the atmosphere –Much lower threshold –Better energy resolution Having a much bigger deep layerHaving a much bigger deep layer –Much better background rejection –Allow us to keep many more gammas that hit the detector without rejecting them Optical Isolation of the PMTsOptical Isolation of the PMTs –Better timing which gives better angular reconstruction –Better background rejection –Better Energy Resolution

14. Jordan Goodman HAWC Review - December 2007 HAWC Detector Design From Milagro to HAWC: Increase Altitude to 4100 m from 2650 mIncrease Altitude to 4100 m from 2650 m Increase Area to 22,000 m 2 from 4,000 m 2 (top layer) or 2,200m 2 (bottom layer)Increase Area to 22,000 m 2 from 4,000 m 2 (top layer) or 2,200m 2 (bottom layer) Reuse 900 Milagro PMTs and front end electronicsReuse 900 Milagro PMTs and front end electronics Equipment Cost $7.4MEquipment Cost $7.4M HAWC 15 x Sensitivity of Milagro:HAWC 15 x Sensitivity of Milagro: Improved  /h Sep., better angle recon, better energy res., lower threshold –HAWC: Detect Crab in ~ 1 day (5  ) –Milagro: Detect Crab in 3 months

15. Jordan Goodman HAWC Review - December 2007 HAWC Scientific Goals Constrain the origin of cosmic rays via HAWC’s observations of  -rays up to 100 TeV from discrete sources and the Galactic plane.Constrain the origin of cosmic rays via HAWC’s observations of  -rays up to 100 TeV from discrete sources and the Galactic plane. Probe particle acceleration in extreme magnetic and gravitational fields via HAWC’s observations of transient TeV sources, such as gamma ray bursts and supermassive black holes.Probe particle acceleration in extreme magnetic and gravitational fields via HAWC’s observations of transient TeV sources, such as gamma ray bursts and supermassive black holes. Explore new TeV physics via HAWC’s unbiased sky survey with a detection threshold of ~30 mCrab in two years.Explore new TeV physics via HAWC’s unbiased sky survey with a detection threshold of ~30 mCrab in two years.

16. Jordan Goodman HAWC Review - December 2007 HAWC Sensitivity is 15x Better than Milagro’s e  (a)Larger Effective Area at Lowest Energies (b)Better Angular Resolution (c)Improved Background Rejection => 15 x improvement in flux sensitivity => 15 2 x faster to observe same flux (a) (b) (c) 100 GeV 1 TeV 10TeV 100 TeV Hadron Efficiency Ang. Res. (deg) Eff. Area (m 2 )

17. Jordan Goodman HAWC Review - December 2007 HAWC Sensitivity to a Crab-like Spectrum 1 Crab 0.01 Crab HESS/VERITAS, MAGIC, Whipple, sensitivity in 50 hours, (~0.2 sr/year)HESS/VERITAS, MAGIC, Whipple, sensitivity in 50 hours, (~0.2 sr/year) GLAST sensitivity in 1 year (4  sr)GLAST sensitivity in 1 year (4  sr) HAWC, Milagro, sensitivity in 1 (dashed) and 5 (solid) years (2  sr)HAWC, Milagro, sensitivity in 1 (dashed) and 5 (solid) years (2  sr) HAWC will do better for hard & diffuse sourcesHAWC will do better for hard & diffuse sources

18. Jordan Goodman HAWC Review - December 2007 HAWC’s Field of View = 2.6  sr = 1.8  sr

19. Jordan Goodman HAWC Review - December 2007 HAWC Detector Design 900 water tanks Tanks are 5 meter diameter and 4.3 meter deep Tanks cost $4.1k each (inc. shipping) One 8” PMT/tank Tank array covers area of 150m x 150m with 78% coverage DAQ trailer Road HAWC Tank Array in GEANT 4

20. Jordan Goodman HAWC Review - December 2007 Tanks vs Pond Less expensiveLess expensive Build incrementallyBuild incrementally –Develop & debug as we are building –Within 2 yrs HAWC will have 4x Milagro sensitivity Expandable, Reconfigurable & upgradeableExpandable, Reconfigurable & upgradeable GEANT4 Simulation Muon (thinned 1/50) produces up to 100s of pes depending on impact parameter 100 MeV  ray (thinned 1/200) produces 1pe/60 MeV independent of impact parameter

21. Jordan Goodman HAWC Review - December 2007 Site Location is Sierra Negra, Mexico 4100 m above sea level4100 m above sea level We have permits to use the siteWe have permits to use the site Easy AccessEasy Access 2 hr drive from Puebla2 hr drive from Puebla 4 hr drive from Mexico City4 hr drive from Mexico City Existing InfrastructureExisting Infrastructure Few km from the US/Mexico Large Millimeter TelescopeFew km from the US/Mexico Large Millimeter Telescope Power, Internet, RoadsPower, Internet, Roads Sierra Negra Scientific Consortium of ~7 projectsSierra Negra Scientific Consortium of ~7 projects Excellent Mexican CollaboratorsExcellent Mexican Collaborators ~15 Faculty at 7 institutions have submitted proposal to CONACyT for HAWC~15 Faculty at 7 institutions have submitted proposal to CONACyT for HAWC Experience in HEP, Auger, and astrophysics (including TeVExperience in HEP, Auger, and astrophysics (including TeV)

22. Jordan Goodman HAWC Review - December 2007 HAWC Collaboration USA: Los Alamos National Laboratory Brenda Dingus, John Pretz, Gus Sinnis University of Maryland Jordan Goodman, Andrew Smith, Greg Sullivan, Vlasios Vasileiou, David Berley, Robert Ellsworth University of Utah Dave Kieda University of New Mexico John Matthews Michigan State University Jim Linnemann Pennsylvania State University Ty DeYoung NASA/Goddard Space Flight Center Julie McEnery Naval Research Laboratory Aous Abdo University of New Hampshire James Ryan University of California, Irvine Gaurang Yodh University of California, Santa Cruz Michael Schneider Mexico: Instituto Nacional de Astrofísica Óptica y Electrónica (INAOE) Alberto Carramiñana, Eduardo Mendoza Universidad Nacional Autónoma de México (UNAM) Instituto de Astronomía: Magdalena González, Dany Page, William Lee, Hector Hernández, Deborah Dultzin, Erika Benitez Instituto de Física: Arturo Menchaca, Rubén Alfaro, Andres Sandoval, Ernesto Belmont Instituto de Ciencias Nucleares: Lukas Nellen, G. Medina-Tanco Instituto de Geofísica: José Valdés Galicia, Alejandro Lara Benemérita Universidad Autónoma de Puebla Humberto Salazar, Oscar Martínez, Cesar Álvarez, Arturo Fernández Universidad Michoacana de San Nicolás de Hidalgo Luis Villaseñor CINVESTAV Arnulfo Zepeda Universidad de Guanajuato David Delepine, Gerardo Moreno, Marco Reyes, Luis Ureña, Victor Migenes Blue - currently in Milagro Red - not currently in Milagro

23. Jordan Goodman HAWC Review - December 2007 Summary Milagro pioneered the water-Cherenkov technique for wide field TeV gamma ray astronomyMilagro pioneered the water-Cherenkov technique for wide field TeV gamma ray astronomy It has made numerous discoveries, showing the importance and complementarity of a wide field instrument to the ACTs, satellites and other instrumentsIt has made numerous discoveries, showing the importance and complementarity of a wide field instrument to the ACTs, satellites and other instruments HAWC is an obvious next stepHAWC is an obvious next step For a modest cost, HAWC can do important and timely physicsFor a modest cost, HAWC can do important and timely physics We have the capability, we have the site, we have the people (we even have the PMTs)We have the capability, we have the site, we have the people (we even have the PMTs) We need your approval (and the money)We need your approval (and the money)