The Te V Sky with HAWC Brenda Dingus

The Te. V Sky with HAWC Brenda Dingus US Spokesperson Los Alamos National Lab dingus@lanl. gov 8 August 2014 1 July 2014

Gamma-Ray Detectors HAWC is a wide field of view (~2 sr), continuously operating (>90% duty cycle), Te. V observatory. Unbiased search for transients to initiate multi messenger observations Highest energy observations with ~100 km 2 hr exposure after 5 years operation on > ½ the sky Wide Field of View, Continuous Operations Te. V Sensitivity Fermi AGILE EGRET HAWC ARGO Milagro VERITA SHESS MAGIC 2

HAWC Design builds on Milagro “ 1 st Generation” Water Cherenkov gamma-ray detector • 2650 m (8600’) elevation near Los Alamos, NM • Covered pond of 4000 m 2 • Operated 2000 -2008 • Detected new Galactic sources, Galactic plane, cosmic ray anisotropy, and put upper limits on prompt emission from gamma-ray bursts HAWC “ 2 nd Generation” Water Cherenkov gamma -ray detector • 4100 m (13500’) elevation near Puebla, Mexico • 300 water tanks spread over 25000 m 2 • Construction 2010 -14, Operation 2013 -19 • 15 x Milagro’s sensitivity with 10 x lower energy threshold ©Aurore Simonnet 3

HAWC Design 300 close packed water tanks (7. 3 m dia x 4. 5 m deep of 200, 000 liters) each with 4 upward facing photomultiplier tubes at the bottom 180 meters 0 14 ters e m 4

HAWC Site Location in Mexico • High Altitude Site of 4100 m with temperate climate and existing infrastructure • 17 R. L. of atmospheric overburden vs 27 R. L. at sea level • Latitude of 19 deg N HAWC Large Millimeter Telescope (50 m dia. dish) Pico de Orizaba 5600 m (18, 500’) 5

The HAWC Collaboration • • • • Los Alamos National Laboratory Univ. of Maryland Michigan State University of Wisconsin Pennsylvania State Univ, of Utah Univ. California Irvine George Mason University of New Hampshire University of New Mexico Michigan Technological University NASA/Goddard Space Flight Center Georgia Institute of Technology University of Alabama Colorado State Univ. California Santa Cruz • • • Instituto Nacional de Astrofísica Óptica y Electrónica Universidad Nacional Autónoma de México • Instituto de Física • Instituto de Astronomía • Instituto de Geofisica • Instituto de Ciencias Nucleares Benemérita Universidad Autónoma de Peubla Universidad Autónoma de Chiapas Universidad Autónoma del Estado de Hidalgo Universidad de Guadalajara Universidad Michoacana de San Nicolás de Hidalgo Centro de Investigacion y de Estudios Avanzados Universidad de Guanajuato ~100 Members Mexico USA 6

11/2010 13 M USD project funding began Feb 2011 Operations with 111 water Cherenkov detectors began Aug 2013 Currently, 264 water tanks have been built. Construction will be complete by end of 2014 02/2012 08/2012 05/2013 01/2014 7

Construction Progressing Well Steel Survey Water PMTs 8

HAWC-30 Completed Sept 2012 HAWC 30 Events and Observation of cosmic-ray shadow of Moon with 70 days of data 9

HAWC-95/111 Skymap 10

HAWC-95/111 Skymap Crab Nebula 11

HAWC-95/111 Skymap Mrk 501 Blazar 12

HAWC-95/111 Skymap Mrk 421 Blazar 13

HAWC Differential Sensitivity per Quarter Decade of Energy http: //arxiv. org/abs/1306. 5800 Astroparticle Physics 2013 14

HAWC Integral Sensitivity vs. Declination vs. High Energy Cut off http: //arxiv. org/abs/1306. 5800 Astroparticle Physics 2013 15

HAWC’s Field Of View Known. Te. V sources are shown, but most of the high latitude sky has not been observed at Te. V energies Sources from Te. VCAT. uchicago. edu 16

Highest Energy Sources For example, MGRO J 2019+37 SED peaks >10 Te. V. Aliu, et al. 2014, “Spatially resolving MGR 0 2019+37 with VERITAS HAWC will likely discover new higher energy peaked sources. 17

Cygnus: A Complicated Region • MGRO J 2031+41: - Collocated extended emission detected by IACTs, Milagro, and ARGO - Spectrum appears to line up with the Fermi cocoon cosmic ray acceleration model can explain the diffuse emission in the cocoon © M. Hui Milagro contours on Fermi counts map 18

HAWC: Extended Sources Milagro’s Detection of an extended excess coincident with Geminga PAMELA’s positron excess is well fit given Milagro’s flux from Geminga ~ 10 parsec Yüksel, Kistler, Stanev PRL 2009 HAWC will detect Geminga with >50 s to measure spectra and map diffusion near source. 19

HAWC: Active Galactic Nuclei Flares ~50 known Te. V AGN • IACT observations have <1% duty cycle/AGN & detect no flaring in many HAWC’s will monitor all Northern AGN with 20% duty cycle/day (5 hrs) regardless of sun, moon, or weather HAWC’s 5 s sensitivity is (10, 1, 0. 1) Crab in (3 min, 5 hrs, 1/3 yr) Worldwide Dataset of Te. V Observations by IACTs of Mrk 421 1 month 3 minutes 5 hours Tluczykont et al. 2010 20

HAWC: Distant Sources • Te. V g-rays are attenuated by pair production • Te. V spectra from distant sources probe: • Cosmology of Extragalactic Background Light • Sources of UHECRs • Intergalactic Magnetic Field in Voids Essey, Kalashev, Kusenko, Beacom, PRL 2010 • Axion Like Particles g a g (Hooper & Serpico, PRL 2007) HAWC will survey sky for new Te. V AGN, measure multi-Te. V spectra and variability, and enable multimessenger observations through prompt notification of flaring activity. Te. V spectra extend beyond pair production threshold for many sources (Horns&Meyer 2012) 21

HAWC: Gamma-Ray Bursts Fermi observation of GRB 090510, z=0. 9 • Highest Observed Energy was 33 Ge. V with 16 g-rays >1 Ge. V • Constrained Lorentz Invariance at the Plank Mass scale GRB 130427: Fermi detected 94 Ge. V g-ray HAWC would detect this GRB if it occurred in FOV 22

HAWC: GRB sensitivity GRB 130427 z=0. 34 z=0. 91 Abeysekara et al. , Astroparticle Physics, 2011 • Fermi LAT sensitivity assumes 1 gamma-ray > 10 Ge. V • Scaler sensitivity uses sum of single photoelectron rates in individual PMTs to observe shortest and most distant transients • Gilmore & Taboada, NIM A 2013 predict HAWC will detect 1. 6 GRBs/yr 23

HAWC: Dark Matter • HAWC has sensitivity to indirect detection of Te. V WIMPs in satellite galaxies, the Galactic Center, and galaxy clusters • Cosmological simulations predict more satellite galaxies than observed • Higher M/L galaxies have been found by Sloan Deep Survey • HAWC will observe all M/L galaxies in half the sky, even if L=0 • Solid lines are 5 sigma sensitivity. • Dashed lines show sensitivity with the expected Sommerfeld enhancement due to additional resonances. Preliminary • Horizontal line is the cross section for thermal production of WIMPs. 24

HAWC: Cosmic Rays Milagro Discovered an Anisotropy of 10 Te. V Cosmic Rays (PRL, 2009) • Confirmed in Northern Hemisphere by ARGO and now HAWC, and in Southern Hemisphere by Ice Cube • • • Gyroradius of 10 Te. V proton in 2 m. G field is 0. 005 parsecs=1000 AU No known sources within this distance Heliospheric Effect? Annihilation in protons of nearby Dark Matter? (Harding, astroph/1307. 6537) Strangelets (stable quark matter)? (Kotera, Perez-Garcia, Silk astroph/1303. 1186 v 1) 25

• Increase photodetection efficiency for lower energies • Winston Cones • Large Area Photodetectors • Liquid Scintillator • Larger Area Array • Sensitivity proportional to Area, NOT sqrt(Area) due to background rejection E d. N/d. E (arbitrary scale) Beyond HAWC: Increase Sensitivity HAWC Single photoelectron threshold Energy of Secondary Particles in Air Shower at Ground Level (Me. V) Muons have broad lateral distribution 26

Beyond HAWC: Southern Site • Discovering rare transient events requires full sky coverage • GRB finder for Advanced LIGO, which will detect all neutron binary coalescence with z<0. 5 • AGN flares & GRBs as distant probes of high energy physics (e. g. Lorentz invariance and axions) • Galactic Center • Te. V Source finder for CTA south Alto Chorrillo Argentina 4800 m 27

Beyond HAWC: Even Lower Energy • Same detector at a higher altitude has increased sensitivity especially at lower energies • Factor of 4 increase in sensitivity between ALMA and HAWC altitude Sensitivity for one year of observation of an array of 900 tanks with 900 PMTs at different altitudes 28

HAWC is now! • Construction complete in 2014 • Science operations with 111 tanks began 1 Aug 2013 • First results are coming now HAWC detects Crab>10 s 29

BACKUP 30

HAWC Performance Much Better Low Energy Response Much Better Background Rejection (b) (a) HAWC Milagro HAWC (c) Better Energy Resolution HAWC Much Better Angular (d) Resolution

Gammas 8 Te. V at ϴ=10° 838 Hit PMTs 21 Te. V at ϴ=21° 1131 Hit PMTs 24 Te. V at ϴ=44° 837 Hit PMTs Protons 118 Te. V at ϴ=52° 1116 Hit PMTs 7 Brian Baughman - HAWC Energy deposited Collaboration - ICRC 2013 Rioaway from core 32

Extensive Air Shower Development 4100 m 2600 m • Higher Altitude means fewer radiation lengths and more particles (~5 x) for same primary energy