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Your search keyword '"Wiebel-Sooth, B."' showing total 4 results
Start Over Author "Wiebel-Sooth, B." Topic astrophysics
4 results on '"Wiebel-Sooth, B."'

1. Search for gamma-ray bursts above 20 TeV with the HEGRA AIROBICC Cherenkov array

Author

HEGRA collaboration, Padilla, L., Funk, B., Krawczynski, H., Contreras, J. L., Moralejo, A., Aharonian, F., Akhperjanian, A. G., Barrio, J. A., Beteta, J. G., Cortina, J., Deckers, T., Fonseca, V., Gebauer, H. -J., Gonzalez, J. C., Heinzelmann, G., Horns, D., Kornmayer, H., Lindner, A., Lorenz, E., Magnussen, N., Meyer, H., Mirzoyan, R., Petry, D., Plaga, R., Prahl, J., Prosch, C., Rauterberg, G., Rhode, W., Roehring, A., Sahakian, V., Samorski, M., Schmele, D., Stamm, W., Wiebel-Sooth, B., Willmer, M., and Wittek, W.

Subjects
Astrophysics
Abstract

A search for gamma-ray bursts (GRBs) above 20 TeV within the field of view (1 sr) of the HEGRA AIROBICC Cherenkov array (29N, 18W, 2200 m a.s.l.) has been performed using data taken between March 1992 and March 1993. The search is based on an all-sky survey using four time scales, 10 seconds, 1 minute, 4 minutes and 1 hour. No evidence for TeV-emission has been found for the data sample. Flux upper limits are given. A special analysis has been performed for GRBs detected by BATSE and WATCH. Two partially and two fully contained GRBs in our field of view (FOV) were studied. For GRB 920925c which was fully contained in our FOV, the most significant excess has a probability of 7.7 10**-8 (corresponding to 5.4 sigmas) of being caused by a background fluctuation. Correcting this probability with the appropriate trial factor, yields a 99.7% confidence level for this excess to be related to the GRB (corresponding to 2.7 sigmas). This result is discussed within the framework of the WATCH detection., Comment: 8 pages, 8 figures. Accepted for publication in A&A

Published
1998

2. An Upper Limit on the Infrared Background Density from HEGRA data on Mkn501

Author

Funk, B., Magnussen, N., Meyer, H., Rhode, W., Westerhoff, S., and Wiebel-Sooth, B.

Subjects
Astrophysics
Abstract

The energy spectrum of Mkn501 in the TeV energy regime, as measured by the HEGRA (High Energy Gamma Ray Astronomy) Cerenkov telescopes during its low state in 1995/96 and during a fraction of the 1997 outburst in the TeV energy regime, is shown to place stringent upper limits on the still unknown infrared photon density in the energy region between 3 x 10**(-3) and 3 xt 10**(-1) eV. Assuming two different shapes for the unknown infrared photon spectrum in this energy range we calculate upper limits on the infrared photon density on the basis of the power-law fit obtained for the observed spectrum up to the maximum energy., Comment: 11 pages, 6 Postscript figures, Accepted for publication in Astroparticle Physics

Published
1998
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3. Measurement of the radial distribution of Cherenkov light generated by TeV gamma-ray air showers

Author

Aharonian, F. A., Akhperjanian, A. G., Barrio, J. A., Bernlöhr, K., Bojahr, H., Contreras, J. L., Juan Cortina, Daum, A., Deckers, T., Fonseca, V., Fraß, A., Gonzalez, J. C., Heinzelmann, G., Hemberger, M., Hermann, G., Heß, M., Heusler, A., Hofmann, W., Hohl, H., Holl, I., Horns, D., Ibarra, I., Kankanyan, R., Kestel, M., Kirstein, O., Köhler, C., Konopelko, A., Kornmayer, H., Kranich, D., Krawczynski, H., Lampeitl, H., Lindner, A., Lorenz, E., Magnussen, N., Meyer, H., Mirzoyan, R., Moralejo, A., Padilla, L., Panter, M., Petry, D., Plaga, R., Prahl, J., Prosch, C., Pühlhofer, G., Rauterberg, G., Rhode, W., Röhring, A., Samorski, M., Schmele, D., Schröder, F., Stamm, W., Ulrich, M., Völk, H. J., Wiebel-Sooth, B., Wiedner, C. A., Willmer, M., and Wirth, H.

Subjects
Physics, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Gamma ray, Astrophysics::Instrumentation and Methods for Astrophysics, HEGRA, FOS: Physical sciences, Astronomy and Astrophysics, IACT, Radial distribution, Astrophysics, Shower, Air shower, High Energy Physics::Experiment, Cherenkov radiation, Zenith
Abstract

Using air showers induced by TeV gamma-rays from Mrk 501, the radial distribution of Cherenkov light is investigated. The shower geometry is reconstructed from the stereoscopic shower images obtained with the telescopes of the HEGRA IACT system. We observe a change in the shape of the light pool with shower energy, and with zenith angle. Data are well reproduced by Monte-Carlo air shower simulations., Comment: 15 Pages, 8 figures, Latex

Published
1998
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4. The time structure of Cherenkov images generated by TeV gamma-rays and by cosmic rays

Author

Heß, M., Bernlöhra, K., Daum, A., Hemberger, M., Hermann, G., Hofmann, W., Lampeitl, H., Aharonian, F. A., Akhperjanian, A. G., Barrio, J. A., Beteta, J. J. G., Contreras, J. L., Juan Cortina, Deckers, T., Fernandez, J., Fonseca, V., Gonzalez, J. C., Heinzelmann, G., Heusler, A., Hohl, H., Holl, I., Horns, D., Kankanyan, R., Kestel, M., Kirstein, O., Köhler, C., Konopelko, A., Kornmayer, H., Kranich, D., Krawczynski, H., Lindner, A., Lorenz, E., Magnussen, N., Meyer, H., Mirzoyan, R., Moralejo, A., Padilla, L., Panter, M., Petry, D., Plaga, R., Prahl, J., Prosch, C., Pühlhofer, G., Rauterberg, G., Rhode, W., Röhring, A., Samorski, M., Sanchez, J. A., Schmele, D., Schröder, F., Stamm, W., Völk, H. J., Wiebel-Sooth, B., Wiedner, C. A., and Willmer, M.

Subjects
Physics, Photon, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), Gamma ray, Astrophysics::Instrumentation and Methods for Astrophysics, HEGRA, FOS: Physical sciences, Astronomy and Astrophysics, Cosmic ray, Astrophysics, law.invention, Core (optical fiber), Telescope, Shower, law, Cherenkov radiation
Abstract

The time profiles of Cherenkov images of cosmic-ray showers and of gamma-ray showers are investigated, using data gathered with the HEGRA system of imaging atmospheric Cherenkov telescopes during the 1997 outbursts of Mrk 501. Photon arrival times are shown to vary across the shower images. The dominant feature is a time gradient along the major axis of the images. The gradient varies with the distance between the telescope and the shower core, and is maximal for large distances. The time profiles of cosmic-ray showers and of gamma-ray showers differ in a characteristic fashion. The main features of the time profiles can be understood in terms of simple geometrical models. Use of the timing information towards improved shower reconstruction and cosmic-ray suppression is discussed., Comment: 25 Pages, 16 figures, Latex

Published
1998
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