The Attenuation Of Atmospheric Cerenkov Photons
Creators: name: Daniel, Michael
Publisher: name: Zenodo
Year: 2002
Subjects: gamma ray astronomy
binaries
atmospheric monitoring
instrumentation

description: Whilst the atmosphere places a limit on the successful applications of many branches of astronomy, it becomes an invaluable tool for the detection of very high energy γ-rays. This thesis is concerned with reducing the systematic uncertainties inherent to using the atmosphere as a detector of very high energy radiation. The interaction processes important to high energy particles are met in the first chapter. The second chapter explores how these interaction processes are responsible for generating observable Cerenkov radiation that can be detected by ground based telescopes. A description of one of these atmospheric Cerenkov telescopes, the University of Durham Mark 6 telescope, is given in chapter 3. A timing analysis was performed on data obtained with this telescope of the high mass X-ray binary Centaurus X-3 and the findings are given in chapter 5. The result of the test for orbital modulation of the VHE γ-ray signal has implications for the possible site of VHE γ-ray emission in this system and for the analysis strategy required to test for modulation of the VHE signal at the pulsar period. One of the findings of the timing analysis was a need for more accurate flux estimates and spectral energy measurements of the VHE γ-ray signal, which requires a greater understanding of the systematic errors inherent to the atmospheric Cerenkov technique. The effective collecting area of a Cerenkov telescope is related to the generation and attenuation of Cerenkov photons in the atmosphere. Uncertainties in the magnitude of the effective area result in errors in the deduced flux, whilst uncertainties in the function of effective area with energy result in errors of the spectral slope determined for any source. By using an inappropriate model for the atmosphere in simulations of atmospheric Cerenkov telescopes a systematic error can be introduced into calculations of the effective area. Chapter 6 compares the effective areas obtained from several model atmosphere types, including a contemporary model of the conditions at the Mark 6 site from data taken with atmospheric monitoring equipment employed in the Mark 6 operations. The findings from this work are then all drawn together in the final chapter, along with a discussion of the future atmospheric monitoring work that will go in to the next generation of atmospheric Cerenkov telescope installations.
description: PhD thesis
description: {"references": ["F. A. Aharonian and A. M. Atoyan. Ap. J., 381, 220\u2013227 (1991).", "F. A. Aharonian and A. M. Atoyan. Space Sci. Rev., 75, 357\u2013373, (1996).", "F. A. Aharonian, A. G. Akhperjanian, J. A. Barrio, K. Bernl\u00a8ohr, H. Bojahr, O. Bolz, H. B\u00a8orst, J. L. Contreras, J. Cortina, S. D. V. Fonseca, J. C. Gonzalez, N. G\u00a8otting, G. Heinzelmann, G. Hermann, A. Heusler, W. Hofmann, D. Horns, A. Ibarra, C. Iserlohe, I. Jung, R. Kankanyan, M. Kestel, J. Kettler, A. Kohnle, A. Konopelko, H. Kornmeyer, D. Kranich, H. Krawczynski, H. Lampeitl, E. Lorenz, F. Lucarelli, N. Magnussen, O. Mang, H. Meyer, R. Mirzoyan, A. Moralejo, L. Padilla, M. Panter, R. Plaga, A. Plyasheshnikov, J. Prahl, G. P\u00a8uhlhofer,W. Rhode, A. R\u00a8ohring, G. Rowell, V. Sahakian, M. Samorski, M. Schilling, F. Schr\u00a8oder, M. Siems, W. Stamm, M. Tluczykont, H. J. V\u00a8olk, C. Wiedner and W. Wittek. A&amp;A, 361, 1073\u20131078 (2000).", "F. Aharonian, A. Akhperjanian, J. Barrio, K. Bernl\u00a8ohr, H. B\u00a8orst, H. Bojahr, O. Bolz, J. Contreras, J. Cortina, S. Denninghoff, V. Fonseca, J. Gonzalez, N. G\u00a8otting, G. Heinzelmann, G. Hermann, A. Heusler, W. Hofmann, D. Horns, A. Ibarra, C. Iserlohe, I. Jung, R. Kankanyan, M. Kestel, J. Kettler, A. Kohnle, A. Konopelko, H. Kornmeyer, D. Kranich, H. Krawczynski, H. Lampeitl, M. Lopez, E. Lorenz, F. Lucarelli, N. Magnussen, O. Mang, H. Meyer, R. Mirzoyan, A. Moralejo, E. Ona, L. Padilla, M. Panter, R. Plaga, A. Plyasheshnikov, J. Prahl, G. P\u00a8uhlhofer, G. Rauterberg, A. R\u00a8ohring, W. Rhode, G. P. Rowell, V. Sahakian, M. Samorski, M. Schilling, F. Schr\u00a8oder, M. Siems, W. Stamm, M. Tluczykont, H. J. V\u00a8olk, C. A. Wiedner and W. Wittek. A &amp; A, 370, 112-120 (2001).", "F. A. Aharonian, A. K. Konopelko, H. J. V\u00a8olk and H. Quintana. Astropart. Phys., 15 335\u2013356 (2001).", "P. Armstrong, P. M. Chadwick, P. J. Cottle, J. E. Dickinson, M. R. Dickinson, N. A. Dipper, S. E. Hilton, W. Hogg, J. Holder, T. R. Kendall, T. J. L. McComb, C. M. Moore, K. J. Orford, S. M. Rayner, I. D. Roberts, M. D. Roberts, M. Robertshaw, S. E. Shaw, K. Tindale, S. P. Tummey and K. E. Turver. Exp. Ast., 9, 51\u201380 (1999).", "T. D. C. Ash, A. P. Reynolds, P. Roche, A. J. Norton, M. D. Still and L. Morales-Rueda. M.N.R.A.S., 307 357\u2013364 (1999).", "M. C. B. Ashley and J. S. Jurcevic. Proc. Ast. Soc. Aus., 9, 334\u2013335 (1991).", "A. M. Atoyan and F. A. Aharonian. M.N.R.A.S., 302 253\u2013276 (1999).", "A.M. Atoyan, K.-M. Aye, P.M. Chadwick, M. K. Daniel, K. Lyons, T. J. L.McComb, J. M. McKenny, S. J. Nolan, K. J. Orford, J. L. Osborne and S. M. Rayner. A&amp;A, 383, 864\u2013880 (2002).", "W. Bednarek. A&amp;A, 362, 646\u2013654 (2000).", "A. R. Bell. The acceleration of cosmic rays in shock fronts. I. M.N.R.A.S., 182, 147\u2013156 (1978).", "A. R. Bell. The acceleration of cosmic rays in shock fronts. II. M.N.R.A.S., 182, 443\u2013455 (1978).", "L. Bergstr\u00a8om, P. Ullio and J. H. Buckley. Astropart. Phys., 9, 137\u2013162 (1998).", "K. Bernlohr. Astropart. Phys., 12, 255\u2013268 (2000).", "G. R. Blumenthal and R. J. Gould. Rev. Mod. Phys., 42, 237\u2013269 (1970).", "B. Boroson, T. Kallman and S. D. Vrtilek. Ap. J., 562, 925\u2013935 (2001).", "K. T. S. Brazier, et al. In Proc. 21st Int. Cosmic Ray Conf. (Adelaide), 2, 296 (1990).", "D. J. Buckley, M. C. Dorrington, P. J. Edwards, T. J. L. McComb, S. P. Tummey and K. E. Turver. Exp. Ast., 9, 237\u2013249 (1999).", "L. Burderi, T. Di Salvo, N. R. Robba, A. La Barbera and M. Guainazzi. Ap. J., 530, 429\u2013440 (2000).", "M. Catanese, C. W. Akerlof, H. M. Badran, S. D. Biller, I. H. Bond, P. J. Boyle, S. M. Bradbury, J. H. Buckley, A. M. Burdett, J. Bussons Gordo, D. A. Carter-Lewis, M. F. Cawley, V. Connaughton, D. J. Fegan, J. P. Finley, J. A. Gaidos, T. Hall, A. M. Hillas, F. Krennrich, R. C. Lamb, R .W. Lessard, C. Masterson, J. E. McEnery, G. Mohanty, J. Quinn, A. J. Rodgers, H. J. Rose, F. W. Samuelson, M. S. Schubnell, G. H. Sembroski, R. Srinivasan, T. C. Weekes, C. W. Wilson and J. Zweerink. Ap. J, 501, 616-623 (1998).", "M. F. Cawley, D. J. Fegan, K. Harris, P. W. Kwok and A. M. Hillas. Exp. Ast., 1, 173\u2013193 (1990).", "M. F. Cawley in Towards a major atmospheric Cerenkov detector II, 176 (Calgary 1993).", "P. M. Chadwick, N. A. Dipper, I. W. Kirkman, T. J. L. McComb and K. J. Orford. In NATO ASIC Proc. 199: Very High Energy Gamma Ray Astronomy, p. 121\u2013123 (1987).", "P. M. Chadwick, T. J. L. McComb and K. E. Turver. J. Phys. G: Nucl. Part. Phys., 16, 1773\u20131803 (1990).", "P. M. Chadwick, M. R. Dickinson, N. A. Dipper, T. R. Kendall, T. J. L. McComb, K. J. Orford, J. L. Osborne, S. M. Rayner, I. D. Roberts, S. E. Shaw and K. E. Turver. Ap. J., 503, 391\u2013395 (1998).", "P. M. Chadwick, K. Lyons, T. J. L. McComb, K. J. Orford, J. L. Osborne, S. M. Rayner, S. E. Shaw, K. E. Turver and G. J. Wieczorek. Ap. J., 513, 161-167 (1999).", "P. M. Chadwick, K. Lyons, T. J. L. McComb, K. J. Orford, J. L. Osborne, S. M. Rayner, I. D. Roberts, S. E. Shaw and K. E. Turver. J. Phys. G.: Nucl. Part. Phys., 25, 1223\u20131233 (1999).", "P. M. Chadwick, K. Lyons, T. J. L. McComb, K. J. Orford, J. L. Osborne, S. M. Rayner, I. D. Roberts, S. E. Shaw and K. E. Turver. J. Phys. G.: Nucl. Part. Phys., 26, L5\u2013L9 (2000).", "P. M. Chadwick, M. K. Daniel, K. Lyons, T. J. L. McComb, J. M. McKenny, S. J. Nolan, K. J. Orford, J. L. Osborne, S. M. Rayner and K. E. Turver. A&amp;A, 364, 165\u2013169 (2000).", "G. Chodil, H. Mark, R. Rodrigues, F. Seward, C. D. Swift, G. Hiltner, G. Wallerstein and E. J. Mannery. Phys. Rev. Lett., 19, 681\u2013683 (1967).", "G. W. Clark, J. R. Minato and G. Mi. Ap. J., 324, 974\u2013994 (1988).", "Ashok Das and Thomas Ferbel. Introduction to Nuclear and Particle Physics. John Wiley &amp; Sons, Inc, 1994.", "B. L. Dingus, D. E. Alexandreas, R. C. Allen, R. L. Burman and K. B. Butterfield. Phys. Rev. Lett., 61, 1906\u20131909 (1988).", "D. J. Bird et al. In Proc. 25th ICRC (Durban) 5, 353\u2013356 (1997).", "R. W. Clay et al. In Proc. 26th ICRC (Salt Lake City) OG4, 421\u2013424, 1997.", "R. Fender. \u2018Relativistic jets from X-ray binaries.\u2019 In \u2019Astrophysics and Cosmology: a collection of critical thoughts.\u2019 W. Kundt and C. van der Brook, editors, Springer (1999).", "R. Fender. Energetics of jets from X-ray binaries. Astrophysics and Space Science Supplement, 276, 69\u201377 (2001).", "Robert G. Fleagle and Joost A. Businger. An Introduction to Atmospheric Physics, volume 5 of International Geophysics Series. New York Academic Press, second edition, 1963.", "R. Giacconi, H. Gursky, E. Kellogg, E. Schreier and H. Tananbaum. Ap. J., (Lett.), 167, L67\u2013L73 (1971).", "P. W. Gorham, M. F. Cawley, D. J. Fegan, K. G. Gibbs, R. C. Lamb, D. F. Liebing, N. A. Porter, V. J. Stenger and T. C. Weekes. Ap. J., (Lett.), 308, L11\u2013L15 (1986).", "P. C. Gregory and T. J. Loredo. Ap. J., 398, 146\u2013168 (1992).", "A. K. Harding and J. K. Daugherty. Advances in Space Research, 21, 251\u2013254 (1998).", "A. M. Hillas Ann. Rev. Astron. Astrophys., 22, 425\u2013444 (1984).", "A. M. Hillas. In Proc. 19th ICRC (La Jolla), 3, 445 (1985).", "A. M. Hillas. Space Sci. Rev., 75, 17\u201330 (1996).", "D. Horan, H. M. Badran, I. H. Bond, S. M. Bradbury, J. H. Buckley, M. J. Carson, D. A. Carter-Lewis, M. Catanese, W. Cui, S. Dunlea, D. Das, I. de la Calle Perez, M. D\u2019Vali, D. J. Fegan, S. J. Fegan, J. P. Finley, J. A. Gaidos, K. Gibbs, G. H. Gillanders, T. A. Hall, A. M. Hillas, J. Holder, M. Jordan, M. Kertzman, D. Kieda, J. Kildea, J. Knapp, K. Kosack, F. Krennrich, M. J. Lang, S. LeBohec, R. Lessard, J. Lloyd-Evans, B. McKernan, P. Moriarty, D. Muller, R. Ong, R. Pallassini, D. Petry, J. Quinn, N. W. Reay, P. T. Reynolds, H. J. Rose, G. H. Sembroski, R. Sidwell, N. Stanton, S. P. Swordy, V.V. Vassiliev, S.P. Wakely and T.C. Weekes. Ap. J., 571, 753-762 (2002).", "J. B. Hutchings, A. P. Cowley, D. Crampton, J. van Paradus and N. E. White. Ap. J., 229, 1079\u20131084 (1979).", "Sherwood B. Idso. Water Resources Research, 17, 295\u2013304 (1981).", "O. C. de Jager. The analysis and interpretation of VHE gamma ray measurements. PhD thesis, Potschefstroom University, 1987.", "O. C. de Jager, B. C. Raubenheimer and J. W. H. Swanepoel. A&amp;A, 221, 180\u2013190 (1989).", "J. V. Jelley. Cerenkov Radiation and its applications. Pergamon Press for the United Kingdom Atomic Energy Authority, 1958.", "J. G. Jernigan, R. I. Klein and J. Arons. Ap. J., 530, 875\u2013889 (2000).", "P. C. Joss and S. A. Rappaport. ARA&amp;A, 22, 537\u2013592 (1984).", "R. L. Kelley, S. Rappaport, G. W. Clark and L. D. Petro. Ap. J., 268, 790\u2013799 (1983).", "T. Kifune, T. Tanimori, S. Ogio, T. Tamura, H. Fujii, M. Fujimoto, T. Hara, N. Hayashida, S. Kabe, F. Kakimoto, Y. Matsubara, Y. Mizumoto, Y. Muraki, T. Suda, M. Teshima, T. Tsukagoshi, Y. Watase, T. Yoshikoshi, P. G. Edwards, J. R. Patterson, M. D. Roberts, G. P. Rowell and G. J. Thornton. Ap. J. (Lett.), 438, L91-L94 (1995).", "R. I. Klein, J. Arons, G. Jernigan and J. J.-L. Hsu. Ap. J., (Lett), 457, L85\u2013L90 (1996).", "F. X. Kneizys, D. C. Robertson, L. W. Abreu, P. Acharya, G. P. Anderson, L. S. Rothman, J. H. Chetwynd, J. E. A. Selby, E. P. Shettle, W. O. Gallery, A. Berk, S. A. Clough and L. S. Bernstein. \u2018The modtran 2/3 report and lowtran 7 model.\u2019 References 134 Technical report, Ontar Corporation, 9 Village Way, North Andover, MA 01845 (November 1996).", "W. Krzeminski. App. J., (Lett.), 192, L135\u2013L138 (1974).", "F. K. Lamb, C. J. Pethick and D. Pines. Ap. J., 184, 271\u2013290 (1973).", "R. C. Lamb, M. F. Cawley, D. J. Fegan, K. G. Gibbs, P. W. Gorham, A. M. Hillas, D. A. Lewis, N. A. Porter, P. T. Reynolds and T. C. Weekes. Ap. J., (Lett.), 328, L13\u2013L16 (1988).", "S. LeBohec and J. Holder. astro-ph/0208396", "D. A. Lewis, R. C. Lamb and S. D. Biller Ap. J., 369, 479\u2013484 (1991).", "T.-P. Li and Y.-Q. Ma. Ap. J., 272, 317\u2013324 (1983).", "Malcolm Longair. High Energy Astrophysics: particles, photons and their detection, volume 1. Cambridge University Press, second edition, 1992.", "Malcolm Longair. High Energy Astrophysics: stars, the Galaxy and the interstellar medium, volume 2. Cambridge University Press, second edition, 1992.", "V. Mannings. A&amp;A, 258, 335\u2013340 (1992).", "Vincent Mannings. TeV Gamma-Ray Emission From Accreting Binary Pulsars. PhD thesis, University of Durham, 1990.", "K. V. Mardia. Statistics of directional data. Academic Press, 1972.", "I. F. Mirabel and L. F. Rodriguez. ARA&amp;A, 37, 409\u2013443 (1999).", "G. Mohanty, S. Biller, D. A. Carter-Lewis, D. J. Fegan, A. M. Hillas, R. C. Lamb, T. C. Weekes, M. West and J. Zweerink. Astropart. Phys., 9, 15\u201343 (1998).", "H. Muraishi, T. Tanimori, S. Yanagita, T. Yoshida, M. Moriya, T. Kifune, S. A. Dazeley, P. G. Edwards, S. Gunji, S. Hara, T. Hara, A. Kawachi, H. Kubo, Y. Matsubara, Y. Mizumoto, M. Mori, Y. Muraki, T. Naito, K. Nishijima, J. R. Patterson, G. P. Rowell, T. Sako, K. Sakurazawa, R. Susukita, T. Tamura and T. Yoshikoshi. A &amp; A, 354, L57-L61 (2000).", "F. Nagase. Pub. Ast. Soc. Pac., 41, 1\u201379 (1989).", "F. Nagase, R. H. D. Corbet, C. S. R. Day, H. Inoue, T. Takeshima, K. Yoshida and T. Mihara. Ap. J., 396, 147\u2013160 (1992).", "S. J. Nolan. PhD thesis, University of Durham, submitted 2002.", "Carl Nordling and Jonny \u00a8Osterman. Physics Handbook. Chartwell-Bratt Ltd, fourth edition, 1987.", "A. R. North, B. C. Raubenheimer, O. C. de Jager, A. J. van Tonder and G. van Urk. Nature, 326, 567\u2013569 (1987).", "A. R. North, et al. In Proc. 21st Int. Cosmic Ray Conf. (Adelaide), 2, 275 (1990).", "R. A. Ong. Phys. Rep., 305 93\u2013202 (1998).", "K. J. Orford. Exp. Ast., 1, 305\u2013310 (1991).", "W. S. Paciesas, G. N. Pendleton, J. P. Lestrade, G. J. Fishman, C. A. Meegan, R. B. Wilson, T. A. Parnell, R. W. Austin, F. A. Berry and J. M. Horack. \u2018Performance of the large-area detectors for the Burst and Transient Source Experiment (BATSE) on the Gamma Ray Observatory.\u2019 In EUV, X-ray, and gamma-ray instrumentation for astronomy and atomic physics; Proceedings of the Meeting, San Diego, CA, Aug. 7-11, 1989 (A90-50251 23-35). Bellingham, WA, Society of Photo-Optical Instrumentation Engineers, volume 1159, p. 156\u2013164 (November 1989).", "A. A. Panferov. A&amp;A, 351, 156\u2013160 (1999).", "M. Punch, C. W. Akerlof, M. F. Cawley, M. Chantell, D. J. Fegan, S. Fennell, J. A. Gaidos, J. Hagan, A. M. Hillas, Y. Jiang, A. D. Kerrick, R. C. Lamb, M. A. Lawrence, D. A. Lewis, D. I. Meyer, G. Mohanty, K. S O\u2019Flaherty, P. T. Reynolds, A. C. Rovero, M. S Schubnell, G. Sembroski, T. C. Weekes and C. Wilson. nature, 358, 477 (1992).", "A. J. Prata. Q. J. Roy. Met. Soc., 122, 1127\u20131151 (1996).", "J. E. Pringle and M. J. Rees. A&amp;A, 21, 1\u20139 (1972).", "J. Quinn, C. W. Akerlof, S. Biller, J. Buckley, D. A. Carter-Lewis, M. F. Cawley, M. Catanese, V. Connaughton, D. J. Fegan, J. P. Finley, J. Gaidos, A. M. Hillas, R. C. Lamb, F. Krennrich, R. Lessard, J. E. McEnery, D. I. Meyer, G. Mohanty, A. J. Rodgers, H. J. Rose, G. Sembroski, M. S. Schubnell, T. C. Weekes, C. Wilson and J. Zweerink. Ap. J. (Lett.), 456), L83-L86 (1996).", "B. C. Raubenheimer and H. J. Smit. Astropart. Phys., 7, 63\u201371 (1997).", "L. K. Resvanis, A. Szentgyorgyi, J. Hudson, L. Kelley, J. G. Learned, C. Sinnis, V. Stenger, D. D. Weeks, J. Gaidos, M. Kertzman, F. Loeffler, T. Palfrey, G. Sembroski, C.Wilson, U. Camerini, J. P. Finley, W. Fry, J. Jennings, A. Kenter, M. Lomperski, R. Loveless, R. March, J. Matthews, R. Morse, D. Reeder and P. Slane. Ap. J., (Lett.), 328, L9\u2013L12 (1988).", "P. T. Reynolds, M. F. Cawley, D. J. Fegan, A. M. Hillas, P. W. Kwok, R. C. Lamb, M. J. Lang, D. A. Lewis, D. J. Macomb, K. S. O\u2019Flaherty, G. Vacanti and T. C. Weekes. Ap. J., 382, 640\u2013646 (1991).", "R. W. Romani. Ap. J., 470, 469\u2013478 (1996).", "G. P. Rowell, P. G. Edwards, J. R. Patterson and G. J. Thornton. Astropart. Phys., 7, 35\u201348 (1997).", "E. Schreier, R. Levinson, H. Gursky, E. Kellogg, H. Tananbaum and R. Giacconi. App. J., (Lett.), 172, L79\u2013L89 (1972).", "S. E. Shaw. Gamma/Hadron Discrimination using Composite Cherenkov Telescopes. PhD thesis, University of Durham, 1999.", "E. M. Standish. A&amp;A, 233, 252\u2013271 (1990).", "J. H. Swank. Nucl. Phys. B - Proc. Suppl., 69, 12\u201319 (1999).", "T. Takeshima, T. Dotani, K. Mitsuda and F. Nagase. Pub. Ast Soc. Jap., 43, L43\u2013 L50 (1991).", "T. Tanimori, Y. Hayami, S. Kamei, S. A. Dazeley, P. G. Edwards, S. Gunji, S. Hara, T. Hara, J. Holder, A. Kawachi, T. Kifune, R. Kita, T. Konishi, A. Masaike, Y. Matsubara, T. Matsuoka, Y. Mizumoto, M. Mori, M. Moriya, H. Muraishi, Y. Muraki, T. Naito, K. Nishijima, S. Oda, S. Ogio, J. R. Patterson, M. D. Roberts, G. P. Rowell, K. Sakurazawa, T. Sako, Y. Sato, R. Susukita, A. Suzuki, R. Suzuki, T. Tamura, G.J. Thornton, S. Yanagita, T. Yoshida and T. Yoshikoshi. Ap. J. (Lett.), 497, L25-L28 (1998).", "Theriault, J-M. Pure Appl. Opt., 7, 889\u2013905 (1998).", "D. J. Thompson, D. L. Bertsch, C. E. Fichtel, R. C. Hartman, R. Hofstadter, E. B. Hughes, S. D. Hunter, B. W. Hughlock, G. Kanbach, D. A. Kniffen, Y. C. Lin, J. R. Mattox, H. A. Mayer-Hasselwander, C. von Montigny, P. L. Nolan, H. I. Nel, K. Pinkau, H. Rothermel, E. J. Schneid, M. Sommer, P. Sreekumar, D. Tieger and A. H. Walker. Ap. J., Suppl. Ser., 86, 629\u2013656 (1993).", "I. R. Tuohy. M.N.R.A.S., 174, 45P\u201350P (1976).", "G. Vacanti, M. F. Cawley, E. Colombo, D. J. Fegan, A. M. Hillas, P.W. Kwok, M. J. Lang, R. C. Lamb, D. A. Lewis, D. J. Macomb, K. S. O\u2019Flaherty, P. T. Reynolds and T. C. Weekes. Ap. J., 377, 467\u2013479 (1991).", "D. Veberic, A. Filipcic, M. Horvat, D. Zavrtanik and M. Zavrtanik. hep-ex/0202015v3", "W. T. Vestrand, P. Sreekumar and M. Mori. Ap. J., (Lett.), 483, L49\u2013L52 (1997).", "T. C. Weekes and K. E. Turver. \u2018Gamma-ray astronomy from 10-100 GeV: A new approach\u2019. In ESA Recent Advan. in Gamma-Ray Astronomy (SEE N78-11899 02-88), p 279\u2013286 (July 1977).", "T. C. Weekes, M. F. Cawley, D. J. Fegan, K. G. Gibbs, A. M. Hillas, P. W. Kowk, R. C. Lamb, D. A. Lewis, D. Macomb, N. A. Porter, P. T. Reynolds and G. Vacanti. Ap. J., 342, 379\u2013395 (1989).", "T. C. Weekes. Space Sci. Rev., 59, 315\u2013364 (1992).", "N. E. White, J. H. Swank and S. S. Holt. Ap. J., 270, 711\u2013734 (1983).", "T. Yoshikoshi, T. Kifune, S. A. Dazeley, P. G. Edwards, T. Hara, Y. Hayami, F. Kakimoto, T. Konishi, A. Masaike, Y. Matsubara, T. Matsuoka, Y. Mizumoto, M. Mori, H. Muraishi, Y. Muraki, T. Naito, K. Nishijima, S. Oda, S. Ogio, T. Ohsaki, J. R. Patterson, M. D. Roberts, G.P. Rowell, T. Sako, K. Sakurazawa, R. Susukita, A. Suzuki, T. Tamura, T. Tanimori, G. J. Thornton, S. Yanagita and T. Yoshida. Ap. J. (Lett.), 487, L65-L68 (1997)."]}