Observation of Multi-TeV Gamma Rays from the Crab Nebula using the Tibet Air Shower Array.
The Tibet experiment, operating at Yangbajing (4300 m above sea level), is the lowest energy air shower array, and the new high-density array constructed in 1996 is sensitive to gamma-ray air showers at energies as low as 3 TeV. With this new array, the Crab Nebula was observed in multi-TeV gamma-rays and a signal was detected at the 5.5 sigma level. We also obtained the energy spectrum of gamma-rays in the energy region above 3 TeV which partially overlaps those observed with imaging atmospheric Cerenkov telescopes. The Crab spectrum observed in this energy region can be represented by the power-law fit dJ&parl0;E&parr0;&solm0;dE=&parl0;4.61+/-0.90&parr0;x10-12&parl0;E&solm0;3 TeV&parr0;-2.62+/-0.17 cm-2 s-1 TeV-1. This is the first observation of gamma-ray signals from point sources with a conventional air shower array using scintillation detectors.
Amenomori
M
Ayabe
S
Cao
PY
Danzengluobu
Ding
LK
Feng
ZY
Fu
Y
Guo
HW
He
M
Hibino
K
Hotta
N
Huang
Q
Huo
AX
Izu
K
Jia
HY
Kajino
F
Kasahara
K
Katayose
Y
Labaciren
Li
JY
Lu
H
Lu
SL
Luo
GX
Meng
XR
Mizutani
K
Mu
J
Nanjo
H
Nishizawa
M
Ohnishi
M
Ohta
I
Ouchi
T
Ren
JR
Saito
T
Sakata
M
Sasaki
T
Shi
ZZ
Shibata
M
Shiomi
A
Shirai
T
Sugimoto
H
Taira
K
Tan
YH
Tateyama
N
Torii
S
Utsugi
T
Wang
CR
Wang
H
Xu
XW
Yamamoto
Y
Yu
GC
Yuan
AF
Yuda
T
Zhang
CS
Zhang
HM
Zhang
JL
Zhang
NJ
Zhang
XY
Zhaxisangzhu
Zhaxiciren
Zhou
WD
Collaboration)
T