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A sample of 54 selected Active Galactic Nuclei (AGN) has been observed with the HEGRA stereoscopic system of Cherenkov Telescopes between 1996 and 2002 in the TeV energy regime. The observations were motivated by the positive results obtained for Mkn 421 and Mkn 501. The distances of the selected objects vary over a large range of redshifts between z =(More)
TeV γ-rays from the BL Lac object 1ES 1959+650 have been measured during the years 2000 and 2001 with a significance of 5.2σ at a value of 5.3 % of the Crab flux and in May 2002 during strong outbursts with > 23σ at a flux level of up to 2.2 Crab, making 1ES 1959+650 the TeV Blazar with the third best event statistics. The deep observation of 197.4 h has(More)
The Crab Nebula has been observed by the HEGRA (High-Energy GammaRay Astronomy) stereoscopic system of imaging air Čerenkov telescopes (IACTs) for a total of about 200 hrs during two observational campaigns: from September 1997 to March 1998 and from August 1998 to April 1999. The recent detailed studies of system performance give an energy threshold and an(More)
graphicx txfonts xspace document 1ES 1959 + 650M 87 Detection of TeV Gamma-Rays from the BL Lac F. Aharonian1, A. Akhperjanian7, M. Beilicke4, K. Bernlöhr1, H.-G. Börst5, H. Bojahr6, O. Bolz1, T. Coarasa2, J.L. Contreras3, J. Cortina10, S. Denninghoff2, M.V. Fonseca3, M. Girma1, N. Götting4, G. Heinzelmann4, G. Hermann1, A. Heusler1, W. Hofmann1, D. Horns1,(More)
For the first time an excess of photons above an energy threshold of 730 GeV from the giant radio galaxy M 87 has been measured at a significance level above 4σ. The data have been taken during the years 1998 and 1999 with the HEGRA stereoscopic system of 5 imaging atmospheric Cherenkov telescopes. The excess of 107.4±26.8 events above 730 GeV corresponds(More)
Clinical studies of lymphoid malignancies (LMs) have suggested that the descriptive patterns of LMs differ in East Asia compared to Western populations. However, there are very limited available data on population-based, subtype-specific incidence rates of LMs in the East Asian population, particularly in Chinese. Using data from the Hong Kong (HK) Cancer(More)
Using the HEGRA system of imaging atmospheric Cherenkov telescopes, one quarter of the Galactic plane (−2 < l < 85) was surveyed for TeV gammaray emission from point sources and moderately extended sources (Ø ≤ 0.8). The region covered includes 86 known pulsars (PSR), 63 known supernova remnants (SNR) and nine GeV sources, representing a significant(More)
The incidence of chronic lymphocytic leukemia (CLL) in the Asian population is up to 10 times lower than that in Caucasians. Studies on CLL in Asian residents in North America may help to determine the relative genetic and environmental causes of such a difference. Computerized records of CLL incidence from the combined British Columbia (BC) databases (n =(More)
The etiology of plasma cell myeloma (PCM) is largely unknown. Its incidence varies widely in different ethnic groups. Migrant study may help determine the relative contributions of genetic versus environmental factors to PCM pathogenesis. We performed a retrospective review of the computerized records of all patients diagnosed with PCM between 1975 and 2004(More)
OBJECTIVE To examine the secular effects of opportunistic screening for cervical cancer in a rich, developed community where most other such populations have long adopted organised screening. DESIGN, SETTING, AND PARTICIPANTS The analysis was based on 15 140 cases of invasive cervical cancer from 1972 to 2001. The effects of chronological age, time(More)