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Tibet AS  collaboration

A Northern Sky Survey for Both TeV CR anisotropy and -ray Sources with Tibet Air Shower Array. Tibet AS  collaboration. The Tibet AS-gamma Experiment ; Two Analysis Methods; Preliminary Results; Discussion and Conclusions.

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Tibet AS  collaboration

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  1. A Northern Sky Survey forBoth TeV CR anisotropy and -ray Sources with Tibet Air Shower Array Tibet AS collaboration • The Tibet AS-gamma Experiment ; • Two Analysis Methods; • Preliminary Results; • Discussion and Conclusions. 2004.8 Zhang Yi Institute of High Energy Physics

  2. Tibet Air Shower Array • Located at an elevation of 4300 m (Yangbajing , China) • Atmospheric depth 606g/cm2 • Wide field of view • High duty cycle (>90%)

  3. Tibet Air Shower Array Tibet-HD Tibet-III 3,600m2 (in area) Tibet-HD 3,600m2 (in area)

  4. Zenith North Pole MethodI-----Equal-zenith method 6.8°＜zenith<40.0° On-source Off-source

  5. Equal Method II----Global CR. Intensity fitting method Zenith

  6. Large scale anisotropy( method II) DEC ～±0.1% Duldig,PASA,Vol18,No.1 RA.

  7. Large scale anisotropy of diff. Data sample

  8. Large scale anisotropy correction σ=1.258 σ=1.018 After subtraction Before subtraction

  9. Crab • Sky Map List of sky cells with clustered directions (24)having statistic significance larger than 4.0σ. Mrk421

  10. Discussion -----Hot Point (88.8-30.2) b=+5˚ b=+5˚ 4.5 σ 3.7σ b=0˚ b=0˚ b=-5˚ b=-5˚ • SNR counterpart G179.0+2.6, • RA : 88.42 DEC :31.08 • Size (/arc min): 70 • Type: Shell b=+5˚ b=0˚ 5.6 σ b=-5˚

  11. b=+5˚ b=+5˚ b=+5˚ b=0˚ b=0˚ b=0˚ b=-5˚ b=-5˚ b=-5˚ Discussion -----Hot Point (304.3-36.7) ~0 σ • S.W. Cui and C.T. Yan,2003, in Proc. 28th International Cosmic Ray Conference , 2315. 4 σ • EGRET counterpart 3EG J2016+3657 RA :304.008 DEC : 37.2 • Milagro (306.6,38.9) 4.2 σ (Atkins,R., et al 2004, ApJ, 608,680) 2.9 σ 4.5 σ 3.9 σ 4.2 σ 4.4 σ

  12. Discussion -----Is there any extended source? b=+5˚ b=+5˚ b=+5˚ b=+5˚ b=0˚ b=0˚ b=0˚ b=0˚ b=-5˚ b=-5˚ b=-5˚ b=-5˚ 3.6 σ 4.2 σ 2.7 σ 3.9 σ

  13. Up flux limit ( method I)

  14. Conclusions • Large scale anisotropy of CR. intensity with a magnitude about 0.1% are observed in two dimensions in TeV energy range. • Crab and Mrk421 are detected. • No other significant point source is found and give a up-flux limit.

  15. Discussion -----Hot Points • Reported in ICRC2003 *; • In the galactic plane and have EGRET counterpart; • High significance in single HD data or TibetIII data. (304.3, 36.7)-----4.2σ (286.7, 5.6)-----4.6σ * S.W. Cui and C.T. Yan,2003,in Proc. 28th International Cosmic Ray Conference , 2315.

  16. Significances from certain sources

  17. Tibet Excesses

  18. —Azimuthal correction— Ununiform of azimuthal distribution ----in different phase

  19. Large scale anisotropy correction RMS ----In different bin size MC data AS gamma data Bin size (degree)

  20. Significance in diff. bin size (MC data) 4-VS-5 3-VS-4 6-VS-7 5-VS-6

  21. —The Global fitting method— 0.9deg. Normalization and smoothing If I (i ,j) is a complete solution, then const* I (i ,j) is also a solution. rso =resolution

  22. Intensity distribution for different belt along galactic plane

  23. Diff. of two method (Japan-China)

  24. Compton-getting effect

  25. MILAGRO Air Shower Array • Located at Fenton Hill, New Mexico at an elevation of 2630 m. • 80m x 60m x 8 m deep, 723 PMTs

  26. Atkins,R., et al 2004, ApJ, 608,680 Milagro Excesses RA DEC Sigma Upper Limit (Crab) 0.3 34.3 4.7 0.84 37.8 6.7 4.0 1.8 43.6 4.8 4.1 2.0 49.1 22.5 4.0 0.87 79.9 26.8 4.9 0.9783.6 22.0 6.3 NA (Crab) 166.5 38.6 5.8 NA (Mkn 421) 306.6 38.9 4.2 0.78313.0 32.2 4.5 0.85339.1 72.5 4.2 3.02356.4 29.5 4.1 0.84

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