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Erratum: Detection of diffuse TeV gamma-ray emission from the nearby starburst galaxy NGC 253

C. Itoh·R. Enomoto·S. Yanagita·T. Yoshida
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Abstract

The CANGAROO-II telescope observed sub-TeV gamma-ray emission from the nearby starburst galaxy NGC 253. The emission region was extended with a radial size of 0.3-0.6 degree. On the contrary, H.E.S.S could not confirm this emission and gave upper limits at the level of the CANGAROO-II flux. In order to resolve this discrepancy, we analyzed new observational results for NGC 253 by CANGAROO-III and also assessed the results by CANGAROO-II. Observation was made with three telescopes of the CANGAROO-III in October 2004. We analyzed three-fold coincidence data by the robust Fisher Discriminant method to discriminate gamma ray events from hadron events. The result by the CANGAROO-III was negative. The upper limit of gamma ray flux was 5.8% Crab at 0.58 TeV for point-source assumption. In addition, the significance of the excess flux of gamma-rays by the CANGAROO-II was lowered to less than 4 sigma after assessing treatment of malfunction of photomultiplier tubes.

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C. Itoh, R. Enomoto, S. Yanagita, T. Yoshida. 2006-10-10. Erratum: Detection of diffuse TeV gamma-ray emission from the nearby starburst galaxy NGC 253. https://doi.org/10.1051/0004-6361%3A20066244

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