The HAWC (High Altitude Water Cherenkov) Observatory The HAWC Collaboration University of Maryland: Jordan Goodman, Andrew Smith, Greg Sullivan, Jim Braun, David Berley Los Alamos National Laboratory: Gus Sinnis, Brenda Dingus, John Pretz University of Wisconsin: Teresa Montaruli, Stefan Westerhoff, Segev Ben Zvi, Juanan Aguilar, Dan Wahl University of Utah: Dave Kieda, Wayne Springer Univ. of California, Irvine: Gaurang Yodh’ Michigan State University: Jim Linnemann, Kirsten Tollefson, Dan Edmunds George Mason University: Robert Ellsworth Colorado State University: Miguel Mustafa, Dave Warner University of New Hampshire: James Ryan Pennsylvania State University: Tyce DeYoung, Patrick Toale, Kathryne Sparks University of New Mexico: John Matthews, William Miller Michigan Technical University: Petra Hüntemeyer NASA/Goddard Space Flight Center: Julie McEnery, Elizabeth Hays, Vlasios Vasileiou Instituto Nacional de Astrofísica Óptica y Electrónica (INAOE): Alberto Carramiñana, Eduardo Mendoza, Luis Carrasco, William Wall, Daniel Rosa, Guillermo Tenorio Tagle, Sergey Silich Universidad Nacional Autónoma de México (UNAM): Instituto de Astronomía: Octavio Valenzuela, V ladimir Avila-Reese, Marco Martos, Maria Magdalena Gonzalez, Sergio Mendoza, Dany Page, William Lee, Hector Hernández, Deborah Dultzin, Erika Benitez Instituto de Física: Arturo Menchaca, Rubén Alfaro, Varlen Grabski, Andres Sandoval, Ernesto Belmont. Arnulfo Matinez-Davalos Instituto de Ciencias Nucleares: Lukas Nellen, Gustavo MedinaTanco, Juan Carlos D’Olivo Instituto de Geofísica: José Valdés Galicia, Alejandro Lara, Rogelio Caballero Benemérita Universidad Autónoma de Puebla:Humberto Salazar, Arturo Fernández, Caupatitzio Ramirez, Oscar Martínez, Eduardo Moreno, Lorenzo Diaz, Alfonso Rosado, Universidad Autónoma de Chiapas: Cesar Álvarez, Eli Santos Rodriguez, Omar Pedraza Universidad de Guadalajara: Eduardo de la Fuente Universidad Michoacana de San Nicolás de Hidalgo: Luis Villaseñor, Umberto Cotti, Ibrahim Torres, Juan Carlos Arteaga Velazquez Centrode Investigacion y de Estudios Avanzados: Arnulfo Zepeda Universidad de Guanajuato: David Delepine, Gerardo Moreno, Edgar Casimiro Linares, Marco Reyes, Luis Ureña, Mauro Napsuciale, Victor Migenes Georgia Institute of Technology: Ignacio Taboada, Andreas Tepe HAWC Technical Staff: Michael Scheinder, Scott Delay USA Mexico The HAWC Collaboration University of Maryland: Jordan Goodman, Andrew Smith, Greg Sullivan, Jim Braun, David Berley Los Alamos National Laboratory: Gus Sinnis, Brenda Dingus, John Pretz University of Wisconsin: Teresa Montaruli, Stefan Westerhoff, Dan Wahl University of Utah: Dave Kieda, Wayne Springer Univ. of California, Irvine: Gaurang Yodh Michigan State University: Jim Linnemann, Kirsten Tollefson, Dan Edmunds George Mason University: Robert Ellsworth University of New Hampshire: James Ryan Pennsylvania State University: Tyce DeYoung, Patrick Toale, Kathryne Sparks University of New Mexico: John Matthews, William Miller Instituto Nacional de Astrofísica Óptica y Electrónica (INAOE): Alberto Carramiñana, Eduardo Mendoza, Luis Carrasco, William Wall, Daniel Rosa, Guillermo Tenorio Tagle, Sergey Silich Universidad Nacional Autónoma de México (UNAM): Instituto de Astronomía: Octavio Valenzuela, V ladimir Avila-Reese, Marco Martos, Maria Magdalena Gonzalez, Sergio Mendoza, Dany Page, William Lee, Hector Hernández, Deborah Dultzin, Erika Benitez Instituto de Física: Arturo Menchaca, Rubén Alfaro, Varlen Grabski, Andres Sandoval, Ernesto Belmont. Arnulfo Matinez-Davalos Instituto de Ciencias Nucleares: Lukas Nellen, Gustavo MedinaTanco, Juan Carlos D’Olivo Instituto de Geofísica: José Valdés Galicia, Alejandro Lara, Rogelio Caballero Benemérita Universidad Autónoma de Puebla:Humberto Salazar, Arturo Fernández, Caupatitzio Ramirez, Oscar Martínez, Eduardo Moreno, Lorenzo Diaz, Alfonso Rosado, Universidad Autónoma de Chiapas: Cesar Álvarez, Eli Santos Rodriguez, Omar Pedraza Universidad de Guadalajara: Eduardo de la Fuente Michigan Technical University: Petra Hüntemeyer Universidad Michoacana de San Nicolás de Hidalgo: Luis Villaseñor, Umberto Cotti, Ibrahim Torres, Juan Carlos Arteaga Velazquez NASA/Goddard Space Flight Center: Julie McEnery, Elizabeth Hays, Vlasios Vasileiou Centrode Investigacion y de Estudios Avanzados: Arnulfo Zepeda Georgia Institute of Technology: Ignacio Taboada, Andreas Tepe Universidad de Guanajuato: David Delepine, Gerardo Moreno, Edgar Casimiro Linares, Marco Reyes, Luis Ureña, Mauro Napsuciale, Victor Migenes HAWC Technical Staff: Michael Scheinder, Scott Delay USA Mexico HAWC Science Objectives • Discover the origin of cosmic rays by measuring gammaray spectra to 100 TeV – Hadronic sources have unbroken spectra beyond 30-100 TeV – Galactic diffuse gamma rays probe the distant cosmic ray flux • Understand particle acceleration in astrophysical jets with wide field of view, high duty factor observations. – Trigger Multi-Messenger/Multi-Wavelength Observations of Flaring Active Galactic Nuclei (including TeV orphan flares) – Detect Short and Long Gamma-Ray Bursts • Explore new physics via HAWC’s unbiased survey of ½ the sky. – Increase understanding of TeV sources to search for new physics. – Study the local TeV cosmic rays and their anisotropy. HAWC Collaboration April 2010 HAWC Science • Gamma Astronomy with wide FoV and high duty cycle: – Understand particle acceleration in AGN and GRB jets through the discovery of short and long GRBs at > 100 GeV energies and • MWL Target of Opportunity programs on flares; – Understand the sources of Galactic CRs through the observation of galactic sources including extended ones (SNRs in molecular clouds, superbubbles) • Studies on EBL and diffuse gamma emissions. • Hadronic Astronomy: – find evidence of proton acceleration in Galactic CR sources (eg understanding Milagro regions with larger statistics) • Exotic phenomena – photon oscillations in axion-like particles through EBL studies; – Lorentz invariance; – Slow Monopoles and Q-balls. Comparison of Gamma-Ray Detectors Low Energy Threshold EGRET/Fermi Space-based (Small Area) “Background Free” Large Duty Cycle/Large Aperture Sky Survey (< 10 GeV) AGN Physics Transients (GRBs) < 300 GeV High Sensitivity HESS, MAGIC, VERITAS Large Effective Area Excellent Background Rejection Low Duty Cycle/Small Aperture High Resolution Energy Spectra up to ~20 TeV Studies of known sources Surveys of limited regions of sky Large Aperture/High Duty Cycle Milagro, Tibet, ARGO, HAWC Moderate Area Excellent Background Rejection Large Duty Cycle/Large Aperture Unbiased Sky Survey Extended sources Transients (GRB’s) > 100 GeV High Energies up to 100 TeV Intro Milagro and HAWC • Milagro was a first generation wide-field gamma-ray telescope: – Proposed in 1990 – Operations began in 2001/04 – Developed g/h separation • Discovered: • more than a dozen TeV sources • diffuse TeV emission from the Galactic plane • a surprising directional excess of cosmic rays • Showed that most bright galactic GeV sources extend to the TeV • Best instrument for hard spectrum and extended sources • HAWC is the next logical step – It will be 15x more sensitive than Milagro – It can be running in 3 yrs (with Fermi) HAWC Collaboration April 2010 HAWC Science Reviews • PASAG - October 2009 – HAWC is a moderate-priced initiative that will carry out excellent astrophysics using a novel technique; there is also the possibility of surprising results of relevance for particle physics. • NSF Review Panel December 2007: – “There is a strong case for HAWC as a wide field of view survey instrument at the TeV scale.” They concluded the project is well understood and technically ready with a strong collaboration. Milagro Results 15 TeV associations out of 35 likely galactic sources in our field of view Abdo et al. ApJL (accepted) arXiv:0904.1018 GeV Pulsars Produce TeV PWN GeV Emission is pulsed & due to rotation axis misaligned with Magnetic Dipole of ~1012 G TeV Emission is produced by particles further accelerated in the shock interacting with the ambient medium. IMPLICATIONS • TeV PWN are prevalent with GeV pulsars • GeV emission has broad beam Geminga (J0634.0+1745) 10 parsecs 68% PSF Milagro HAWC • Brightest GeV source of 34 searched is Geminga • Old (300 kyr) PWN and nearby (250 pc) • ~10 parsec extent is similar to HESS observations of more distant PWN Milagro sees Geminga at 30% of the Crab at ~20 TeV while IACTs have a limit of ~1% of the Crab at >200 GeV Geminga with HAWC 10 parsecs 68% PSF Milagro HAWC • Brightest GeV source of 34 searched is Geminga • Old (300 kyr) PWN and nearby (250 pc) • ~10 parsec extent is similar to HESS observations of more distant PWN Milagro sees Geminga at 30% of the Crab at ~20 TeV while IACTs have a limit of ~1% of the Crab at >200 GeV Milagro Results Milagro Spectrum of the Crab Milagro 68% HAWC Energy reach from ~3TeV to >100 TeV Peak sensitivity for E-2 source at ~100 TeV HESS Crab data/fit Milagro Spectrum of the Crab w/HAWC Milagro 68% HAWC Energy reach from ~3TeV to >100 TeV Peak sensitivity for E-2 source at ~100 TeV HEGRA Crab data/fit Milagro Results MGRO J2019+37/ 0FGL J2020.8+3649 In Milagro J2019+37 is 700 mCrab The flux in γ/s >200 GeV is 95mCrab Milagro 68% HAWC HESS Crab fit: (Io =3.76x10-7,Γ=2.39, Ec=14.1 TeV) This source is almost as bright as the Crab at Milagro’s energy MGRO J2019+37/ 0FGL J2020.8+3649 In Milagro J2019+37 is 700 mCrab The flux in γ/s >200 GeV is 95mCrab Milagro 68% HAWC HESS Crab fit: (Io =3.76x10-7,Γ=2.39, Ec=14.1 TeV) Milagro Results MGRO J1908+06 Milagro 68% HAWC Ecut 14 40 (156 (2 A Milagro discovered source now seen by HESS and VERITAS Using HESS spectrum of -2.1 as input, Milagro requires a cut-off at <40(56) TeV (N.B. Milagro measures a larger flux, possibly because we are integrating over a larger area than HESS) HAWC Simulation Milagro 3 source detected at 20 HAWC (3months) HAWC Simulation Milagro 3 source detected at 20 HAWC (3months) HAWC Simulation Milagro 3 source detected at 20 HAWC (3months) Milagro Results Diffuse TeV Excess • Whether or not there is a GeV excess, Milagro sees a TeV excess. • This excess could be due to unresolved sources or hadronic cosmic rays hitting matter near their source. • If the TeV excess has a flat spectrum, it is likely hadronic in origin and may not be detectable at GeV energies. – With help from ACTs and Fermi we will do a source subtraction – This will allow us to measure the spectrum and morphology of the excess • This study could point to regions of the galaxy with a higher concentration of cosmic rays than near earth - pointing to sites of acceleration. Abdo et. al ApJ 2008 Active Galactic Nuclei Flares Milagro’s 9 Mrk421 Milagro flux • HAWC makes daily observations without weather, moon, or solar constraints. • HAWC’s 5 sensitivity for Mrk 421 is (10,1,0.1) Crab in (3 min, 5 hrs, 1/3 yr) • HAWC will notify multiwavelength observers in real time of flaring AGN • Study correlations with x-rays, etc to determine emission mechanisms • Discovery potential for orphan TeV flares producing neutrinos and UHECR Quadratic or Linear? Synchrotron Self Compton or External Compton? 1 month Crab Flux X-ray flux Distinguishing New Physics from Astrophysics • Violation of Lorentz Invariance OR Energy Dependent Particle Acceleration – HAWC will detect multiple flaring extragalactic sources (AGN and GRBs) to resolve redshift vs source mechanisms • Cosmological Star Formation OR Spectral Cutoffs in the source – HAWC will trigger multiwavelength observations of flaring AGN to obtain best measured and modeled TeV spectra • Continuum Gamma-Ray Emission from Dark Matter Annihilation OR Astrophysical Source – HAWC will search for time variability which would imply an astrophysical source Milagro Results Cosmic Ray Observations Significance (σ’s) Geminga Heliotail • Milagro data show an unexpected anisotropy (PRL 101, 221101, 2008) • No weighting or cutting. • Map dominated by charged cosmic rays. • 10o smoothing, looking for intermediate sized features. • Two regions of excess 15.0 and 12.7. Fractional excess of 6x10-4 (4x10-4) for region A(B). Milagro Results http://people.roma2.infn.it/~aldo/RICAP09_trasp_Web/Vernetto_ARGO_RICAP09ar.pdf 21 Milagro Results Cosmic Ray Anisotropy • Data are not consistent with: – Mostly gamma-rays –> data looks hadronic – with cosmic ray spectrum –> flatter, with ~10 TeV cutoff • HAWC with better energy resolution and gammahadron rejection can: – Measure the spectrum with much higher precision – Measure the gamma-ray fraction • Understanding this is important for Dark Matter Searches HAWC Collaboration April 2010 Geminga as a Local Cosmic Ray Source • “If the observed cosmic ray excess does indeed arise from the Geminga SN explosion, the long–sought “smoking gun” connecting cosmic rays with supernovae would finally be at hand. - Salvati and Sacco (AA 09) • The confirmed presence of a nearby, ancient source of high-energy electrons and positrons immediately suggests an explanation for the positron excess. -Yüksel, Kistler, Stanev arXiv:0810.2784 PAMELA’s positron excess Fit well given Milagro’s flux from Geminga HAWC Collaboration April 2010