D. Kranich

The Crab Nebula and Pulsar between 500 GeV and 80 TeV: Observations with the HEGRA Stereoscopic Air Cerenkov Telescopes

The Crab supernova remnant has been observed regularly with the stereoscopic system of 5 imaging air Cherenkov telescopes that was part of the High Energy Gamma Ray Astronomy (HEGRA) experiment. In total, close to 400 hours of useful data have been collected from 1997 until 2002. The spectrum extends up to energies of 80 TeV and is well matched by model calculations in the framework of inverse Compton scattering of various seed photons in the nebula including for the first time a recently detected compact emission region at mm-wavelengths. The observed indications for a gradual steepening of the energy spectrum in data is expected in the inverse Compton emission model.The average magnetic field in the emitting volume is determined to be

Evidence for TeV gamma ray emission from Cassiopeia A

(161.6pm0.8mathrm{stat}pm18_mathrm{sys}) mu

First results on the performance of the HEGRA IACT array

G. The presence of protons in the nebula is not required to explain the observed flux and upper limits on the injected power of protons are calculated being as low as 20 % of the total spin down luminosity for bulk Lorentz factors of the wind in the range of

Is the Giant Radio Galaxy M 87 a TeV Gamma-Ray Emitter?

10^4-10^6

An unidentified TeV source in the vicinity of Cygnus OB2

.The position and size of the emission region have been studied over a wide range of energies. The position is shifted by 13arcsec to the west of the pulsar with a systematic uncertainty of 25arcsec. No significant shift in the position with energy is observed. The size of the emission region is constrained to be less than 2arcmin at energies between 1 and 10 TeV. Above 30 TeV the size is constrained to be less than 3arcmin.No indications for pulsed emission has been found and upper limits in differential bins of energy have been calculated reaching typically 1-3 % of the unpulsed component.The Crab supernova remnant has been observed regularly with the stereoscopic system of five imaging air Cerenkov telescopes that was part of the High Energy Gamma Ray Astronomy (HEGRA) experiment. In total, close to 400 hr of useful data have been collected from 1997 to 2002. The differential energy spectrum of the combined data set can be approximated by a power law-type energy spectrum: d?/dE = ?0 ?, ?0 = 10-11?photons?cm-2 s-1 TeV-1, and ? = -2.62 ? 0.02stat ? 0.05sys. The spectrum extends up to energies of 80?TeV and is well matched by model calculations in the framework of inverse Compton scattering of various seed photons in the nebula, including for the first time a recently detected compact emission region at millimeter wavelengths. The observed indications for a gradual steepening of the energy spectrum in data is expected in the inverse Compton emission model. The average magnetic field in the emitting volume is determined to be 161.6 ? 0.8stat ? 18sys ?G. The presence of protons in the nebula is not required to explain the observed flux, and upper limits on the injected power of protons are calculated to be as low as 20% of the total spin-down luminosity for bulk Lorentz factors of the wind in the range of 104-106. The position and size of the emission region have been studied over a wide range of energies. The position is shifted by 13 to the west of the pulsar, with a systematic uncertainty of 25. No significant shift in the position with energy is observed. The size of the emission region is constrained to be less than 2 at energies between 1 and 10?TeV. Above 30?TeV the size is constrained to be less than 3. No indication of pulsed emission has been found, and upper limits in differential bins of energy have been calculated reaching typically 1%-3% of the unpulsed component.

The Energy Spectrum of TeV Gamma Rays from the Crab Nebula as Measured by the HEGRA System of Imaging Air Cerenkov Telescopes

232 hours of data were accumulated from 1997 to 1999, using the HEGRA Stereoscopic Cherenkov Telescope System to observe the supernova remnant Cassiopeia A. TeV γ -ray emission was detected at the

Variations of the TeV energy spectrum at different flux levels of Mkn 421 observed with the HEGRA system of Cherenkov telescopes

5 sigma

TeV gamma rays from the blazar H 1426+428 and the diffuse extragalactic background radiation

level, and a flux of

Correlated Intense X-Ray and TeV Activity of Markarian 501 in 1998 June

(5.8 pm 1.2_{mathrm{stat}} pm 1.2_{mathrm{syst}}) 10^{-9} {ph} {m}^{-2} {s}^{-1}

Detection of TeV gamma-rays from the BL Lac 1ES 1959+650 in its low states and during a major outburst in 2002

above 1 TeV was derived. The spectral distribution is consistent with a power law with a differential spectral index of