The HAWC High Altitude Water Cherenkov Observatory The

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 De. Young, Patrick Toale, Kathryne Sparks University of New Mexico: John Matthews, William Miller Michigan Technical University: Petra Hüntemeyer NASA/Goddard Space Flight Center: Julie Mc. Enery, 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 Medina. Tanco, 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 De. Young, 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 Medina. Tanco, 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 Mc. Enery, 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 Te. V – Hadronic sources have unbroken spectra beyond 30 -100 Te. V – 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 Te. V orphan flares) – Detect Short and Long Gamma-Ray Bursts • Explore new physics via HAWC’s unbiased survey of ½ the sky. – Increase understanding of Te. V sources to search for new physics. – Study the local Te. V cosmic rays and their anisotropy. HAWC Collaboration April 2010

HAWC Science • Gamma Astronomy with wide Fo. V and high duty cycle: – Understand particle acceleration in AGN and GRB jets through the discovery of short and long GRBs at > 100 Ge. V 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 Ge. V) AGN Physics Transients (GRBs) < 300 Ge. V High Sensitivity HESS, MAGIC, VERITAS Large Effective Area Excellent Background Rejection Low Duty Cycle/Small Aperture High Resolution Energy Spectra up to ~20 Te. V 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 Ge. V High Energies up to 100 Te. V

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 Te. V sources • diffuse Te. V emission from the Galactic plane • a surprising directional excess of cosmic rays • Showed that most bright galactic Ge. V sources extend to the Te. V • Best instrument for hard spectrum and extended sources • HAWC is the next logical step – It will be 15 x 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 Te. V scale. ” They concluded the project is well understood and technically ready with a strong collaboration.

Milagro Results 15 Te. V associations out of 35 likely galactic sources in our field of view Abdo et al. Ap. JL (accepted) ar. Xiv: 0904. 1018

Ge. V Pulsars Produce Te. V PWN Ge. V Emission is pulsed & due to rotation axis misaligned with Magnetic Dipole of ~1012 G Te. V Emission is produced by particles further accelerated in the shock interacting with the ambient medium. IMPLICATIONS • Te. V PWN are prevalent with Ge. V pulsars • Ge. V emission has broad beam

Geminga (J 0634. 0+1745) 10 parsecs 68% PSF Milagro HAWC • Brightest Ge. V 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 Te. V while IACTs have a limit of ~1% of the Crab at >200 Ge. V

Geminga with HAWC 10 parsecs 68% PSF Milagro HAWC • Brightest Ge. V 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 Te. V while IACTs have a limit of ~1% of the Crab at >200 Ge. V

Milagro Results Milagro Spectrum of the Crab Milagro 68% HAWC Energy reach from ~3 Te. V to >100 Te. V Peak sensitivity for E -2 source at ~100 Te. V HESS Crab data/fit

Milagro Spectrum of the Crab w/HAWC Milagro 68% HAWC Energy reach from ~3 Te. V to >100 Te. V Peak sensitivity for E -2 source at ~100 Te. V HEGRA Crab data/fit

Milagro Results MGRO J 2019+37/ 0 FGL J 2020. 8+3649 In Milagro J 2019+37 is 700 m. Crab The flux in γ/s >200 Ge. V is 95 m. Crab Milagro 68% HAWC HESS Crab fit: (Io =3. 76 x 10 -7, Γ=2. 39, Ec=14. 1 Te. V) This source is almost as bright as the Crab at Milagro’s energy

MGRO J 2019+37/ 0 FGL J 2020. 8+3649 In Milagro J 2019+37 is 700 m. Crab The flux in γ/s >200 Ge. V is 95 m. Crab Milagro 68% HAWC HESS Crab fit: (Io =3. 76 x 10 -7, Γ=2. 39, Ec=14. 1 Te. V)

Milagro Results MGRO J 1908+06 Milagro 68% HAWC Ecut 14 40 (1σ) 56 (2σ) 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) Te. V (N. B. Milagro measures a larger flux, possibly because we are integrating over a larger area than HESS)

HAWC Simulation Milagro 3σ source detected at 20σ HAWC (3 months)

HAWC Simulation Milagro 3σ source detected at 20σ HAWC (3 months)

HAWC Simulation Milagro 3σ source detected at 20σ HAWC (3 months)

Milagro Results Diffuse Te. V Excess • Whether or not there is a Ge. V excess, Milagro sees a Te. V excess. • This excess could be due to unresolved sources or hadronic cosmic rays hitting matter near their source. • If the Te. V excess has a flat spectrum, it is likely hadronic in origin and may not be detectable at Ge. V 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 Ap. J 2008

Active Galactic Nuclei Flares Milagro’s 9σ Mrk 421 Milagro flux • HAWC makes daily observations without weather, moon, or solar constraints. • HAWC’s 5 σ 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 Te. V 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 Te. V 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. • 10 o smoothing, looking for intermediate sized features. • Two regions of excess 15. 0σ and 12. 7σ. Fractional excess of 6 x 10 -4 (4 x 10 -4) for region A(B).

Milagro Results http: //people. roma 2. infn. it/~aldo/RICAP 09_trasp_Web/Vernetto_ARGO_RICAP 09 ar. 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 Te. V 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 ar. Xiv: 0810. 2784 PAMELA’s positron excess Fit well given Milagro’s flux from Geminga HAWC Collaboration April 2010