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 basedObservation isnecessary

LHC Elab

LHC Ecm

CR spectrum

(Berezhko)

Emax~ Z

3PeV

3EeV

Emax=βZBL

Solar flares:1011eV

SN1006: 1016eV

AGN: 1018-20eV

(Hillas plot)

Crab :1016eV

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 requirementsYBJ Satisfy all the requirements

Requirements on Observation SiteRequirements 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 o3TeV;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.1997. 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 2000-2001 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)1 62.7 51.1 4.2 9 254.8 5.8 4.1

2 83.7 21.8 5.6 10 263.6 21.4 4.1

3 129.3 13.5 4.1 11 286.8 6.0 4.4

4 131.8 33.9 4.3 12 316.5 13.0 4.0

5 137.5 41.8 4.1 13 318.2 40.9 4.1

6 165.7 38.3 5.4 14 331.6 52.5 4.4

7 175.8 2.1 4.4 15 353.3 24.6 4.1

8 221.3 13.6 4.6

Allsky Survey (1999.11-2004.10)PRELIMINARY

Milagro limit

Preliminary

Flux Limit (1999.11-2004.10)

Indirect search of DM

γ>100MeV 　 （ EGRET ）

Diffuse TEV gamma ray from the Galactic Plane

Effective Area

９９％ C.

L.

９９％ C.

L.

９９％ C.

L.

Tibet-III (22,050m2) 1041.3 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 m2 ;

80 channels electronics + 600 channels from shower array

KASCADEKASCADE

e/ Hadron

(~100K channels of electronics ！！！）

J. Huang Primary proton

spectrum(analyses based on

Corsika_QGSJET

and SIBYLL )

(KASCADE data: astro-ph/0312295)

PreliminaryAll

ProtonKASCADE (P)

Present Results -3.11-3.13

PreliminaryAll

Proton

Present Results

KASCADE (P)

Tibet III + MUON

8,640 m2

Number of μ in MUON detector

10TeV 100TeV (gamma)

0.4

（ μ 数＝ 0 　→　 0.12 　と表示）

10TeV 100TeV (gamma)

MAGIC

VERITAS

HESS

Tibet-III

Tibet-III+WC

Detection Sensitivity of Tibet-III+WC (3 years 5σ)

Tibet-III Scintillation Counters 37,000m2

+Underground

Water Cherenkov Detector 8,640m2

Crab orbit

Flat region (> 200TeV)Background << 1 event15 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 byTibet III+WC!

Extrapolation

Consistent withpower low

Design of detector

3.75m

3.75m

20 detectors

20 d

etec

tors

YAC array

Tibet III

YAC

AS

Pb

Iron

Scint.

Box

7cu

ConclusionPb=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