The Gamma-Ray Bright Future: The HAWC Perspective. Michelle Hui for the HAWC Collaboration Michigan Technological University

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1 Gamma-Ray Observatory The Gamma-Ray Bright Future: The HAWC Perspective for the HAWC Collaboration Michigan Technological University What are we learning from the gamma-ray sky? October 12, 2013

2 Gamma-Ray Observatory The Gamma-Ray Bright Future: The HAWC Perspective Present for the HAWC Collaboration Michigan Technological University What are we learning from the gamma-ray sky? October 12, 2013

3 Gamma-Ray Detectors Wide Field of View, Continuous Operations TeV Sensitivity Fermi AGILE EGRET HAWC ARGO Milagro Tibet ASγ VERITAS HESS MAGIC 3

4 Pulsar Wind Nebulae Pulsar Wind Nebulae Most common Galactic TeV source. Many show significant extent. Background for more exotic gamma-ray production mechanisms (dark matter). Gamma-rays from Geminga PWN consistent with PAMELA/AMS data on positron fraction (Yuksel et al. 2009, PRL 3, 0511). Crab flares unexplained. Crab Nebula (Hubble) Continues to TeV inverse-compton emission? Flares in other PWN? Abdo et al. 20, ApJ, 708, 1254 Not ruled out as a potential source of cosmic rays. s 1 ] 2.F [erg cm 2 E 9 11 Fermi CGRO COMPTEL CGRO EGRET HESS MAGIC CANGAROO VERITAS HEGRA CELESTE Energy [MeV] 4

5 Pulsar Wind Nebulae Pulsar Wind Nebulae Most common Galactic TeV source. Many show significant extent. Background for more exotic gamma-ray production mechanisms (dark matter). Gamma-rays from Geminga PWN consistent with PAMELA/AMS data on positron fraction (Yuksel et al. 2009, PRL 3, 0511). Crab flares unexplained. Crab Nebula (Hubble) Continues to TeV inverse-compton emission? Flares in other PWN? Abdo et al. 20, ApJ, 708, 1254 Not ruled out as a potential source of cosmic rays. s 1 ] 9 Fermi CGRO COMPTEL CGRO EGRET HESS MAGIC CANGAROO VERITAS HEGRA CELESTE 2.F [erg cm 2 E 11 Geminga PWN in Milagro Energy [MeV] Abdo et al. 2009, ApJL, 700, 127 4

6 Strong evidence for cosmic-ray acceleration. Supernova Remnants Association of HE emission from molecular clouds. Observation of characteristic pion emission How high does the emission go? Flux implied by Milagro observation of IC443 is x larger than extrapolating VERITAS spectrum. Acciari et al. 2009, ApJL, 98, 133 Abdo et al. 2009, ApJL, 700, 127 Credit: Chandra X-ray: NASA/CXC/B.Gaensler et al; ROSAT X-ray: NASA/ROSAT/Asaoka & Aschenbach; Radio Wide: NRC/DRAO/ D.Leahy; Radio Detail: NRAO/VLA; Optical: DSS 5

7 No. 2, 2009 MILAGRO OBSERVATIONS OF MULTI-TeV EMISSION FROM GALACTIC SOURCES Supernova Remnants Strong evidence for cosmic-ray acceleration. Association of HE emission from molecular clouds. Observation of characteristic pion emission How high does the emission go? Flux implied by Milagro observation of IC443 is x larger than extrapolating VERITAS spectrum. Abdo et al. 2009, Figure 1. 3σ sources from Table 1, omitting J (shown in Figure 2) and the Crab. Each frame shows a 5 5 region with the ApJL, 700, 127 indicated by white dots. The error on the Fermi source locations is quite small on this scale, typically between 0.1 and 0.2 deg, depending on the been smoothed by a Gaussian of width varying between 0. 4 and 1. 0, depending on the expected angular resolution of events. Horizontal axes Acciari et al. and2009, ApJL, vertical axes show declination.98, The colors133 indicate the statistical significance in standard deviations. Figures 1 and 2 show the regions in the Mi measurement of the diffuse emission (Abdo et al. 2008) at its Ackermann et al. 2013, the indicated LAT sources. Eight of the 13 sour highest value, in the inner Galaxy (30 < l < 65, b < 2 ). with previously reported >TeV sources or can Using this807 value, we expect 5.3 TeV s cm in a 1 Science, 339, 0FGL J is the young Crab Pul bin at 35 TeV, which is only about 15% contamination for the weakest sources in Table 1. The GALPROP conventional model, for comparison, would only constitute 3% contamination. The contamination is likely lower than suggested by the Milagro measurement because of unresolved sources, such as many of the sources from Table 1. It has even been suggested (Casanova & Dingus 2008) that most of the Milagro diffuse measurement could be due to unresolved sources. Finally, the Fermi points observed at 3σ in the Milagro data occur near local maxima in the Milagro data. In contrast, the diffuse emission is expected to vary slowly across the Galaxy. 3. DISCUSSION Credit: Chandra X-ray: NASA/CXC/B.Gaensler et al; ROSAT X-ray: NASA/ROSAT/Asaoka & Aschenbach; Radio Wide: NRC/DRAO/ D.Leahy; Radio Detail: NRAO/VLA; Optical: DSS From this analysis, it appears quite common for Galactic 0 MeV to 0 GeV sources to have associated multi-tev emission. This association is notable for pulsars, where 9 of the 16 pulsars from the BSL are on our list of likely multitev emitters. The pulsars in the BSL which have less than 3σ significance in Milagro data tend to lie off the Galactic plane. The pulsars off the plane are typically older, having traveled far from their origin after the kick they received from the initial asymmetric supernova (Gunn & Ostriker 1970). Of the SNR sources on the list, we see three of five. Interestingly, we see only 2 of the 12 unidentified sources. These unidentified sources may be extragalactic and not visible with this analysis which was optimized for multi-tev emission. PWN is a standard reference source in TeV as 0FGL J is associated with SNR interacting with a nearby large molecular clou X-ray feature has been interpreted as a PW 2001), implying the existence of a pulsar, b emission has yet been detected. IC443 was fir 1 TeV by MAGIC (Albert et al. 2007) and la VERITAS (Humensky et al. 2008). The flux r is somewhat higher than the flux predicted the MAGIC fit, but is roughly consistent a the extremes of the statistical and systematic measurements. 0FGL J is the Geminga pulsar. atively old (342 kyr) but very near (250 pc) pu et al. 2005; Halpern & Holt 1992; Faherty et most significant Fermi-LAT source in the north sion over 1 TeV has only been reported by Mil C3 with too low a significance to be classifi detection. Milagro observes an emission regio by several degrees as shown in Figure 2. Th ported in Table 1 has been computed assum emission, but if we instead assume that the sou sion from an extended region and convolve a the energy-dependent point-spread function, t the location of 0FGL J increases cal maximum of the Milagro excess is at R 5

8 Active Galactic Nuclei Blazar Viewing down the jet Black Hole Accretion Disk Quasar/Seyfert 1 Viewing at an angle to the jet Radio Galaxy/Seyfert 2 Viewing at 90 o from the jet Strong flares seen in TeV. Unbiased TeV survey will collect many more flares. Correlation between Synchrotron and Inverse Compton emission. Quadratic or linear? 1998 May April April April April 7 Orphan flares require high-energy trigger March Archival Markarian 501 SED Torus of Neutral Gas and Dust Radio Jet Image: Aurore Simonnet, Sonoma State University Illustration: Robert Naeye, NASA GSFC Tuesday, March 2, 20 6

9 Active Nuclei Blazars andgalactic Active Galactic Nuclei Strong flares seen in TeV. Blazar Viewing down the jet AGN unified model: direction of sight Unbiased TeV survey will collect many more flares. determines the sub-class Quasar/Seyfert 1 Viewing at an angle to the jet Correlation between Synchrotron and Inverse Compton emission. Quadratic or linear? Blazar: viewing down the jet Orphan flares require high-energy trigger. Radio Galaxy/Seyfert 2 Viewing at 90o from the jet γ Black Hole AGN physics: Markarian 501 SED Jet structure Black Hole accretion Emission mechanism1 (leptonic, hadronic) Spectral evolution Variability (inner engine structure) ΦASM,2-keV [ cm-2 s-1] The Astrophysical Journal, 738:25 (19pp), 2011 September 1 (MJD ) 1997 April April Accretion Disk 1998 May April April March Archival 1 Acciari et al VERITAS/PCA [r = 0.77, p = 5.0e-4] Φ2-keV/15-150keV [-9 cm-2 s-1] γ VERITAS/XRT [r = 0.62, p = 0.076] VERITAS/BAT [r = 0.12, p = 0.67] VERITAS/ASM [r = 0.57, p = 7.0e-3] Whipple/PCA [r = 0.60, p = 0.023] Whipple/XRT [r = 0.79, p = 0.035] Whipple/BAT [r = 0.57, p = 7.0e-3] Whipple/ASM [r = 0.35, p = 0.049] 2b(1) 2b(2) 2b(2) Cosmology: EBL characterization and evolution Torus of Neutral Gas and Dust 2b(1) ASM/BAT: tmax = 1h [r = 0.25, p = 0.06] t : 15.0m Fundamental Physics: 1 Lorenz invariance (fast variability) ASM/BAT: tmax = min [r = 0.32, p = 0.17] -1 Radio Jet (Adapted from Buckley, Science, 1998) Image: Aurore Simonnet, Sonoma State University Illustration: Robert Naeye, NASA GSFC HEAD 20 Nicola Galante for the VERITAS coll. Tuesday, March 2, 20 2b(2) -1-9 ΦBAT,15-150keV [ cm-2 s-1] Figure 9. Hard/soft X-ray flux correlation between the kev Swift/BAT flux and the 2 kev RXTE/ASM flux. All dwell-by-dwell flux points with a statistical significance above 2σ measured in the first half of 2008 (MJD ) are shown for two cases of a maximum time lag between the observed data points. The legend gives the corresponding correlation coefficient and the corresponding chance probability for the non-correlation. VERITAS James Table Buckley 3 The HAWC perspective (t T )/τ (t T )/τ r 0 f Φ>300GeV [ cm s-1] -2 Acciari et al. 2011, ApJ, 738, 25 Figure. Correlation between TeV fluxes (VERITAS and Whipple) and X ray fluxes (RXTE: PCA and ASM, Swift: XRT and BAT). All X-ray fluxe are given between 2 and kev, except for the Swift/BAT fluxes which are given between 15 and 150 kev. Only data measured in the first half of 2008 (MJD ) are shown. The RXTE/ASM and Swift/BAT fluxes are dwell by dwell with the requirement that the statistical significance is above two standard deviations. The maximum time difference between the data points i t! 15 minutes. The correlation coefficients including the chance probability for the null hypothesis are shown in the legend. The flux pairs measured during SnowPAC, Salt Lake City, March 20 Parameters of an Exponential Rise/Fall Function (Section 3.4) 0 max 6

10 Gamma-Ray Bursts GRB0905 Massive Star Collapse (Artist) Ackermann et al. 20, ApJ, 716, 1178 Continuation of Fermi-LAT rising GeV component. Assume Fermi GBM trigger, GRB spectra continues up to 1TeV, predicts 1.65 GRBs/year for HAWC (Taboada & Gilmore, arxiv: ). HAWC can be a ground-based trigger for IACTs. 7

11 Gamma-Ray Bursts GRB0905 Massive Star Collapse (Artist) Ackermann et al. 20, ApJ, 716, 1178 Continuation of Fermi-LAT rising GeV component. Assume Fermi GBM trigger, GRB spectra continues up to 1TeV, predicts 1.65 GRBs/year for HAWC (Taboada & Gilmore, arxiv: ). HAWC can be a ground-based trigger for IACTs. simulation 7

12 Dark Matter Additional Science Topics Via Lactea II Simulation Annihilation signatures from High-mass (>1 TeV WIMPs). Direct searches for slow-moving extremely massive Q-ball particles. 8

13 Dark Matter Additional Science Topics Milagro TeV IceCube 20 TeV Via Lactea II Simulation Annihilation signatures from High-mass (>1 TeV WIMPs). Direct searches for slow-moving extremely massive Q-ball particles. Cosmic Ray Anisotropy 8

14 Dark Matter Additional Science Topics Milagro TeV IceCube 20 TeV Via Lactea II Simulation Annihilation signatures from High-mass (>1 TeV WIMPs). Direct searches for slow-moving extremely massive Q-ball particles. Cosmic Ray Anisotropy TeV Diffuse Emission Unbiased Galactic Plane survey 8

15 High Altitude Water Cherenkov Detector Second generation of technique developed for the Milagro gamma-ray observatory ( ). Re-deploying Milagro PMTs and Front-end electronics Sensitive from 0 GeV to 0 TeV. Angular resolution degrees. High altitude (40 m) site at Sierra Negra, Mexico Large tanks of water covering 22,000 m 2 area Overall 15x improvement in sensitivity over Milagro. See the Crab at over 5σ every day. Strengths: Extreme high-energy reach. Wide field-of-view to catch transient emission. 9

16 High Altitude Water Cherenkov Detector Second generation of technique developed for the Milagro gamma-ray observatory ( ). Re-deploying Milagro PMTs and Front-end electronics Sensitive from 0 GeV to 0 TeV. Angular resolution degrees. High altitude (40 m) site at Sierra Negra, Mexico Large tanks of water covering 22,000 m 2 area Overall 15x improvement in sensitivity over Milagro. See the Crab at over 5σ every day. Strengths: Extreme high-energy reach. Wide field-of-view to catch transient emission. 4.5m 7.3m 9

17 Colorado State University Georgia Institute of Technology George Mason University Los Alamos National Laboratory Michigan State University Michigan Technological University University of New Hampshire Pennsylvania State University University of Alabama University of California, Irvine University of California, Santa Cruz University of Maryland University of New Mexico University of Wisconsin-Madison University of Utah Centro de Investigacion en Computacion, Instituto Politecnico Nacional Centro de Investigacion y de Estudios Avanzados del IPN Benemérita Universidad Autónoma de Puebla Universidad Nacional Autónoma de México: Instituto de Astronomía Instituto de Ciencias Nucleares Instituto de Física Instituto de Geofísica Instituto Nacional de Astrofísica, Óptica y Electrónica Universidad Autónoma del Estado de Hidalgo Universidad Michoacana de San Nicolás de Hidalgo Universidad Autónoma de Chiapas Universidad Politecnica de Pachuca Universidad de Guadalajara ~0 members 15 U.S. institutions 13 Mexican institutions

18 Background:!Proton!Tagging! Gamma<Ray!Tagging! Gamma / Hadron Separation Look!for!large!hits!far!from!core!(99%!@!!TeV)! oves!50%!of!gammas!@!!tev! Gamma-Ray Observatory Cosmic!ray! N2! γ! e<! π0! e<! γ! γ! γ! μ+! e<! νμ0 e<! _! νe0 TAUP!2013!<!Asilomar! 12!September!2013! e+! _! νμ0 νμ0! TAUP!2013!<!Asilomar! 9! 11

19 Background:!Proton!Tagging! Gamma<Ray!Tagging! Gamma / Hadron Separation Look!for!large!hits!far!from!core!(99%!@!!TeV)! oves!50%!of!gammas!@!!tev! Gamma-Ray Observatory Cosmic!ray! N2! γ! e<! π0! e<! γ! γ! γ! μ+! e<! νμ0 e<! _! νe0 TAUP!2013!<!Asilomar! 12!September!2013! e+! _! νμ0 νμ0! TAUP!2013!<!Asilomar! 9! 11

20 Performance arxiv: Gamma-Ray Observatory Larger effective area below 0 GeV Much improved hadron rejection. Angular resolutions down to 0.1 o. 12

21 Performance arxiv: Gamma-Ray Observatory Larger effective area below 0 GeV Much improved hadron rejection. Angular resolutions down to 0.1 o. 12

22 Performance arxiv: Gamma-Ray Observatory Larger effective area below 0 GeV Much improved hadron rejection. Angular resolutions down to 0.1 o. 12

23 HAWC Sensitivity arxiv: Gamma-Ray Observatory Competitive sensitivity to IACTs across the entire sky. 13

24 Field of View arxiv: Gamma-Ray Observatory Instantaneous: ~2 sr. 14

25 Field of View arxiv: Gamma-Ray Observatory 5σ /year Instantaneous: ~2 sr. 14

26 Current Status 111/300 tanks taking data. Taking data with 30+ since Fall 12. Operations formally began Aug 1 st. Detector to be completed Summer 14. Clear evidence of gamma rays from Galactic and extra-galactic sources. 15

27 Current Status 111/300 tanks taking data. Taking data with 30+ since Fall 12. Operations formally began Aug 1 st. Detector to be completed Summer 14. Clear evidence of gamma rays from Galactic and extra-galactic sources. 15

28 Moon Shadow Gamma-Ray Observatory The Moon & Sun block part of the cosmic-ray flux causing a shadow on Earth. Early HAWC data: 1 January - 15 April live days. -15σ deficit, consistent with expectations. Position is consistent with geomagnetic deflection. End-to-end check for DAQ through reconstruction software and absolute pointing. 16

29 Sun Shadow Gamma-Ray Observatory Preliminary analysis. Modulated by magnetic field of the Sun. -6.4σ in 145 days livetime. Position is consistent with geomagnetic deflection. Amplitude is consistent with current solar cycle. Can be used to probe solar activity and solar magnetic field. 17

30 Cosmic-Ray Anisotropy Gamma-Ray Observatory Large-scale structure, confirming numerous observations. Few parts in 1x -3 anisotropy Using the forward-backward technique (Abdo et al. 2009, ApJ, 698, 2121). region C? region B region A Small-scale ( ) structure originally discovered by Milagro. 1 part in 5x -4 anisotropy. One region coincident with heliotail. Nearby CR source with magnetic funneling? Geminga? (Salvati & Sacco, A&A 2008) Dark Matter Annihilation? (Harding, arxiv: ) 18

31 GRB A GRB!130427A:!HAWC<30! Gamma-Ray Observatory Brightest GRB detected in 30 years (2 x -3 erg/cm2). photon Extremely!bright!source:! observed. 94 GeV <3!erg!cm<2!(highest!in!30! 2 (z=0.34). Low redshiftyears)! and setting for HAWC. 57 zenith angle 94!GeV!photon!observed! HAWC main DAQ was offline, PMT rates recorded by scaler DAQ. found in 6 search windows (GCN circular 14549). No excess HAWC!measurement:! D.!Lennarz,!ICRC!!2013! if near zenith! Would be ~5σ Main!DAQ!off! summed PMT rate and moving average Scaler!DAQ!on! GRB!@!57!zenith!and!se5ng0 No!signal!in!6!0me!windows! (GCN!Circular!14549)! Would!be!~5σ!if!near!zenith! tember!2013! TAUP!2013!<!Asilomar! 20! 19

32 Crab Nebula: First Look Gamma-Ray Observatory Crab (Dec +22 deg) transits near zenith and is observed 5-6 hr per day. ~2.5 months of HAWC-95 and HAWC-111 exposure over a 3- month period. ~6σ at the Crab position. PRELIMINARY Caveats: Absolute pointing uncertainties. Very preliminary calibration. Subset of the data reconstructed online. Many small analysis issues TBD yet. 20

33 AGN: Mrk 421 and Mrk 501 Gamma-Ray Observatory PRELIMINARY PRELIMINARY Mrk 421: 5.4σ at the source position. Mrk 501: 5.5σ at the source location. Time dependence under analysis. Caveats: Absolute pointing uncertainties. Very preliminary calibration. Subset of the data reconstructed online. Many small analysis issues TBD yet. 21

34 Summary Gamma-Ray Observatory HAWC is a new instrument for multi-tev astronomy and astrophysics. Wide field-of-view: detect rare extremely high-energy photons and continuously monitor the sky for transients. Early data analysis underway: Confirmed shadow of the Sun and the Moon. Confirmed cosmic-ray anisotropy. Evidence of gamma rays from the Crab Nebula, Mrk 421, and Mrk 501. Clear signal from the Galactic plane. Analysis underway. Full detector to be completed in ~1 year. Transient alerts soon. 22

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