A Northern Sky Survey for Both TeV CR anisotropy and  -ray Sources with Tibet Air Shower Array Hongbo Hu For Tibet AS  collaboration The Tibet AS-gamma Experiment ; Two Analyses Methods; Preliminary Results; Discussion and Conclusions Institute of High Energy Physics

YangBaJing Observatory and its Experiments –Located at an elevation of 4300 m (Yangbajing, China) –Atmospheric depth 606g/cm 2 –Wide field of view –High duty cycle (>90%) ARGO Experimental Hall ASγ air shower array

3,600m 2 (in area) Tibet-HD Tibet array: ~250 x 250 m 2 HD: 60 x 60m 2 Tibet-III: ~150x150 m 2 Tibet-III Tibet-HD Operation Time Live Time Selected Events Mode Energy Resolution ) Area Tibet- HD ~ days1.5×10 9 ~3TeV0.9 o 3600m 2 Tibet-III ~ days5.5×10 9 ~3TeV0.9 o 22050m 2 Tibet Air Shower Array

Method I -----Equal-zenith method Zenith North Pole On-source Off-source 6.8°< zenith <40.0° Making use of the fact that events are uniformly distributed within equal-zenith belt; 10 off-source windows (side band) are chosen to estimate BKG.

Equal ! Method II----Global CR. Intensity fitting method Zenith Equal ? All sky survey based on an anisotropy correction of relative CR intensity, which is obtained by LSQ fitting for the data in each of equal zenith ring

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

Large scale anisotropy of diff. Data sample Anisotropy measurements agree with each other from using HD detector or TibetIII detector, means small systematic effects.

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

 Sky Map NO.R.A.(˚)DEC(˚)Signifi(σ)NO.R.A.(˚) Signifi(σ) * * * * * * * Crab Mrk421 List of sky cells with clustered directions (24)having statistic significance larger than 4.0σ. (88.8,30.2)

Discussion Hot point I ---evt. No.9 (88.8°, 30.2 °) SNR counterpart G , RA : DEC :31.08 Size (/arc min): 70 Type: Shell 3.7σ 4.5 σ 5.6 σ b=+5˚ b=0˚ b=-5˚ b=+5˚ b=0˚ b=-5˚

Hot Point II - - No.18(304.3 °, 36.7 °), No19(309.9 °, 39.6 °) Amenomori,in Proc.27 th ICRC,2315. Observed 4.15 σ; S.W. Cui and C.T. Yan, in Proc. 28 th ICRC, Observed 4 σ; EGRET counterpart 3EG J RA : DEC : 37.2 Milagro (306.6,38.9) 4.2 σ (Atkins,R., et al 2004, ApJ, 608,680) ~0 σ 4.2 σ b=+5˚ b=0˚ b=-5˚ b=+5˚ b=0˚ b=-5˚ b=+5˚ b=0˚ b=-5˚ 3.9 σ 4.4 σ 4.5 σ 2.9 σ

Up flux limit (by method I) (30 degree of declination related to YBJ zenith direction)

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 with 5 σ level. No other significant point source is found, and an upper-flux limit curve is given