Detection of gamma rays of up to 50 TeV from the Crab Nebula

T. Tanimori, K. Sakurazawa, S. A. Dazeley, P. G. Edwards, T. Hara, Y. Hayami, S. Kamei, T. Kifune, T. Konishi, Y. Matsubara, T. Matsuoka, Y. Mlzumoto, A. Masaike, M. Mori, H. Muraishi, Y. Muraki, T. Naito, S. Oda, S. Ogio, T. OsakiJ. R. Patterson, M. D. Roberts, G. P. Rowell, A. Suzuki, R. Suzuki, T. Sako, T. Tamura, G. J. Thornton, R. Susukita, S. Yanagita, T. Yoshida, T. Yoshikoshi

Research output: Contribution to journalArticlepeer-review

96 Citations (Scopus)


Gamma rays with energies greater than 7 TeV from the Crab pulsar/Crab Nebula have been observed at large zenith angles, with the imaging atmospheric technique from Woomera, South Australia. CANGAROO data taken in 1992, 1993, and 1995 indicate that the energy spectrum extends up to at least 50 TeV, without a change of the index of the power-law spectrum. The observed differential spectrum is (2.01 ± 0.36) × 10-3(E/7w TeV)-233±018 TeV-1 cm-2 s-1 between 7 and 50 TeV. There is no apparent cutoff. The spectrum for photon energies above ∼10 TeV allows the maximum particle acceleration energy to be inferred and implies that this unpulsed emission does not originate near the light cylinder of the pulsar but in the nebula, where the magnetic field is not strong enough to allow pair creation from the TeV photons. The hard gamma-ray energy spectrum above 10 TeV also provides information about the varying role of seed photons for the inverse Compton process at these high energies, as well as a possible contribution of π° gamma rays from proton collisions.

Original languageEnglish
Pages (from-to)L33-L36
JournalAstrophysical Journal
Issue number1 PART II
Publication statusPublished - 1998
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'Detection of gamma rays of up to 50 TeV from the Crab Nebula'. Together they form a unique fingerprint.

Cite this