Recent Asγ results +History+Future Introduction –Brief history of the experiment Recent results –γ ray observation –Knee physics Future plan –MUON dector –“Shower” Core detector

Steepenning spectrum: Ground based Observation is necessary LHC E lab LHC E cm CR spectrum (Berezhko) E max ~ Z 3PeV 3EeV

E max =βZBL Solar flares:10 11 eV SN1006: eV AGN: eV (Hillas plot) Crab :10 16 eV

宇宙线在地球 大气层中引发 广延大气簇射 (Extensive Air Shower) 的原理示意图

Advantage of YangBaJing altitude (4300M) –Number of secondary reach maximum, in favor of knee physics, including composition and spectrum measurement. –Low energy threshold, in favor of γ ray astronomy –Better angular,energy resolution γ ray astronomy knee (Ong)

90km NW from Lhasa ~1º slope; 4300 m a.s.l. 90º53’E, 30º11’N Shigatse YBJ Satisfy all the requirements

Requirements on Observation Site high quality operation, low cost and long life-span: Altitude 4300m a.s.l. Topography flat and wide, plenty of space. Climate easy for construction, operation & living. Traffic accessible to highway, airport or railway station. Power existed electric power line network. Logistics not far from local town/modern city. Neighborhood 1000s of residents: clinic, post office, school … Communication Telephone, mobile phone, high speed optical fibre network (155Mbps today).

History of ASγ development BD(1996) 3TeV;1700Hz;0.87 o 3TeV;115Hz;0.9 o ;

中意合作 ARGO 实验 RPC 大厅 中日合作 AS γ 实验区闪烁体探测器阵列 ARGO hall, floored by RPC. Half installed. Asγ,ARGO (High Duty cycle,Large F.O.V) ~TeV~100GeV MILAGRO, Jemez （ 2630M ） e  AS γ scintillation counter

Gamma ray emission from Crab (TibetII-HD : 5.5σ,ApJ 525,L93,1999)

Mrk501 (TibetII HD) ApJ 532,302(2000) Feb.1997-Aug Only observation from conventional air shower array.

Mrk421 (6.9σ) AS γ 比切伦可夫望远镜更长时间地观测了 年间 Mrk421 的爆发。

太阳宇宙线 1) 最先观测到宇宙线太阳阴影； 2 ）寻找与太阳耀斑， GLE 事件相伴随的高能宇宙线发射。

NO.R.A.(˚)DEC(˚)Sig.(σ)NO.R.A.(˚)DEC(˚)Sig(σ) Allsky Survey ( ) PRELIMINARY

Milagro limit Preliminary Flux Limit ( )

Indirect search of DM

γ>100MeV （ EGRET ） Diffuse TEV gamma ray from the Galactic Plane Effective Area ９９％ C.L. Tibet-III (22,050m 2 ) days (1999 Nov.~2004 Oct.)

Two dimensional observation on large scale anisotropy of TeV Cosmic-ray using the Tibet Air Shower Array (Preliminary)

EC and BD Total EC area : 80 m 2 ; 80 channels electronics channels from shower array

KASCAD E e/  Hadron (~100K channels of electronics ！！！）

J. Huang Primary proton spectrum (analyses based on Corsika_Q GSJET and SIBYLL ) (KASCADE data: astro-ph/ ) Preliminary All Proton KASCADE (P) Present Results Preliminary All Proton Present Results KASCADE (P)

Tibet III + MUON 8,640 m 2

Number of μ in MUON detector 10TeV100TeV (gamma) 0.4 （ μ 数＝ 0 → 0.12 と表示） 10TeV100TeV (gamma)

MAGIC VERITAS HESS Tibet-III Tibet-III+WC Detection Sensitivity of Tibet-III+WC (3 years 5σ) Tibet-III Scintillation Counters 37,000m 2 + Underground Water Cherenkov Detector 8,640m 2 Crab orbit Flat region (> 200TeV) Background << 1 event 15 photon sensitivity (Poisson 5σ)

Energy Spectrum of HESS sources Indices are harder Aharonian et al, ApJ, 636, 777 (2006) (If it is constructed in the southern hemisphere) Most of HESS sources detectable by Tibet III+WC! Extrapolation Consistent with power low

Design of detector 3.75m 20 detectors YAC array Tibet III YAC AS Pb Iron Scint. Box 7cu Conclusion Pb=7cu, Spacing=3.75m, Nb>100

Primary energy range M. Shibata

Summary YangBaJing is an unparalleled observatory AS γ has been very successful Looking forward to seeing TIBET-III/MUON, HAWC & other projects will get going in YBJ