Portada.ps (46 Kb.)

Contents.ps (237 Kb.)

Introduction ( Introduction.ps (31 Kb.))

Physical Basis ( Chapter1.ps (11.800 Kb.))

Cherenkov Radiation

Extensive Air Showers

Cherenkov Radiation in EAS

The Imaging Atmospheric Cherenkov Technique ( Chapter2.ps (11.852 Kb.))

Cherenkov Telescopes

Gamma/hadron Separation Technique

Image Parameters

Image Moment Estimation

Image Parameters in the context of the Gamma/hadron Separation Method

On the Use of Polarization in IACTs ( Chapter3.ps (799 Kb.))

Basic Physical Ideas

Implications

Operational Setup ( Chapter4.ps (772 Kb.))

Introduction

Extensive Air Showers Simulation

CORSIKA Physics

Cherenkov Radiation in CORSIKA

CORSIKA parameters and applied modifications

Detector Simulation

Ray Tracing

Light of the Night Sky

Image Analysis

Monte Carlo Data Base

Results ( Chapter5.ps (2.634 Kb.))

General Characteristics

Energy Threshold

Image Parameters

Conclucions ( Chapter6.ps (242 Kb.))

Bibliography ( Bibliography.ps (241 Kb.))

List of Figures ( Figures.ps (265 Kb.))

List of Tables ( Tables.ps (236 Kb.))

A study of the polarization of the Cherenkov Radiation in Extensive Air Showers of Energy around 1 TeV.

Presented as a Poster in the 16th European Cosmic Ray Simposium in Alcalá de Henares, Madrid, July 20-24, 1998.

A study of the effect of polarizing filters in Imaging Cherenkov Telescopes

Presented as a Poster in the TeV Workshop in Snowbird, Utah 1999.

Postscript file with the proceedings: proceed.ps (237 Kb.)

A possible use for polarizers in Imaging Atmospheric Cherenkov Telescopes.

Astorparticle Physics, Vol/Issue 17/2, pp.133-149, 2002.

(astro-ph/0107271)

Ref: 26th International Cosmic Ray Conference ; Salt Lake City, Utah 1999; August 17-25, 1999 (OG 4.3.19)

Simulation and experimental studies of polarization properties of atmospheric Cerenkov pulses

Authors: Bhat, C. L.; Rannot, R. C.; Mahapatra, D. K.; Gandhi, V. N.; Tickoo, A. K.; Kaul, R.; Kaul, S. K.; Kaul, S. R. Goyal, H. C.; Bhatt, N.

Bhabha Atomic Research Centre, Nuclear Research Laboratory, Trombay, Mumbai-400085, India

Ref: Bulletin of the Astronomical Society of India, vol. 27, p.343.

My Current Work

Currently I am working at the Universtity of Leeds in the Department of physics and Astronomy inside the Whipple Group . I joint the gruop in October 1999.

At the moment I am working in the development of the analog transport of a signal throught a fiber optic system and its application to the Atmospheric Cherenkov Telescopes.

Design and performance of analog fiber optic links used on the Whipple 10 metre air Cherenkov telescope.

Authors:I. H. Bond, S. M. Bradbury, I. de la Calle, P. A. Ogden, H. J. Rose and T. C. Weekes

University of Leeds, Department of Physics and Astronomy, LS2 9JT Leeds, UK

Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, P.O. Box 97, Amado, AZ 85645-0097, USA

The use of fiber optics instead of coaxial cable for signal transmission can reduce pulse dispersion and attenuation and so will allow a shorter ADC gate to be used. Results indicate that the night sky background component could be reduced by ~25 %. A prototype system of links has been installed on the Whipple 10 m air Cherenkov telescope and the performance has been assessed over one year of operation. The bandwidth is 150 MHz and the dynamic range of the output is from 2 mV to 1 mV. The average gain of the 120 channels is 4.1 and is stable to within a few percent over a typical 3 week observation period. The baseline noise level is 0.5 mV rms but this can increase to 6 mV amplituede at certain resonance points in the value of the laser bias current. The deviation from true linearity is typically less than 7% .

To be presented at the 2001 ICRC Hamburg, Germany.

Search for TeV Gamma Ray emission from 4C39.12 with the Whipple 10 metre Cherenkov Telescope

Authors:I. de la Calle and S. M. Bradbury for the VERITAS collaboration.

University of Leeds, Department of Physics and Astronomy, LS2 9JT Leeds, UK

Among others, the Whipple telescope has been used over the past decade in the search for VHE emission from BL Lacertae objects applying different target selection criteria. Here we report on a new candidate, 4C39.12, a radio selected source in 408 the MHz B2 survey which includes Mrk421 and Mrk501. Given its low redshift (z=0.02), the close similarities to Mrk421 and Mrk501 and the recent identification of a relativistic jet at a small angle with respect to the line of sight (0 < 45 deg) 4C39.12 is a fair candidate for VHE emission. This object has not been catalogued by EGRET but it is detected by ROSAT at a level consistent with non-thermal emission from the core and is classified as an X-ray selected BL Lac in some references. Over a period of 5 months the Whipple Telescope has been monitoring the object for evidence of emission above 300 GeV. A 99.99 % confidence upper limit to the flux is derived from these observations.

To be presented at the 2001 ICRC Hamburg, Germany.

Group Publications

HEGRA

The time averaged TeV energy spectrum of Mkn 501 of the extraordinary 1997 outburst as measured with the stereoscopic Cherenkov telescope system of HEGRA.

F.A. Aharonian, A.G. Akhperjanian, J.A. Barrio, K. Bernlohr, H. Bojahr, I. Calle, J.L. Contreras, J. Cortina, A. Daum, T. Deckers, S. Denninghoff, V. Fonseca, J.C. Gonzalez, G. Heinzelmann, M. Hemberger, G. Hermann, M. Heb, A. Heusler, W. Hofmann, H. Hohl, D. Horns, A. Ibarra, R. Kankanyan, J. Kettler, C. Kohler, A. Konopelko, H. Kornmeyer, M. Kestel, D. Kranich, H. Krawczynski, H. Lampeitl, A. Lindner, E. Lorenz, N. Magnussen, H. Meyer, R. Mirzoyan, A. Moralejo, L. Padilla, M. Panter, D. Petry, R. Plaga, A. Plyasheshnikov, J. Prahl, G. Puhlhofer, G. Rauterberg, C. Renault, W. Rhode, A. Rohring, V. Sahakian, M. Samorski, D. Schmele, F. Schroder, W. Stamm, H.J. Volk, B. Wiebel-Sooth, C. Wiedner, M. Willmer, W. Wittek

Ref:1999A&A...349...11A.

Correlated intense X-Ray and TeV activity of Mkn 501 in 1998 june.

F.A. Aharonian, A.G. Akhperjanian, J.A. Barrio, K. Bernlohr, H. Bojahr, I. Calle , J.L. Contreras, J. Cortina, A. Daum, T. Deckers, S. Denninghoff, V. Fonseca, J.C. Gonzalez, G. Heinzelmann, M. Hemberger, G. Hermann, M. Heb, A. Heusler, W. Hofmann, H. Hohl, D. Horns, A. Ibarra, R. Kankanyan, J. Kettler, C. Kohler, A. Konopelko, H. Kornmeyer, M. Kestel, D. Kranich, H. Krawczynski, H. Lampeitl, A. Lindner, E. Lorenz, N. Magnussen, H. Meyer, R. Mirzoyan, A. Moralejo, L. Padilla, M. Panter, D. Petry, R. Plaga, A. Plyasheshnikov, J. Prahl, G. Puhlhofer, G. Rauterberg, C. Renault, W. Rhode, A. Rohring, V. Sahakian, M. Samorski, D. Schmele, F. Schroder, W. Stamm, H.J. Volk, B. Wiebel-Sooth, C. Wiedner, M. Willmer, W. Wittek

Ref:2000ApJ...538..127S.

The temporal characteristics of the TeV -emission from Mkn 501 in 1997. II. Results from HEGRA CT1 and CT2.

F. Aharonian, A.G. Akhperjanian, J.A. Barrio, K. Bernlohr, H. Bojahr, I. Calle, J.L. Contreras, J. Cortina, A. Daum, T. Deckers, S. Denninghoff, V. Fonseca, J. Gebauer, J.C. Gonzalez, G. Heinzelmann, M. Hemberger, G. Hermann, M. Hess, A. Heusler, W. Hofmann, H. Hohl, D. Horns, A. Ibarra, R. Kankanyan, M. Kestel, O. Kirstein, C. Kohler, H. Kornmayer, D. Kranich, H. Krawczynski, H. Lampeitl, A. Lindner, E. Lorenz, N. Magnussen, H. Meyer, R. Mirzoyan, A. Moralejo, L. Padilla, M. Panter, D. Petry, R. Plaga, A. Plyasheshnikov, J. Prahl, G. Puhlhofer, G. Rauterberg, C. Renault, W. Rhode, A. Rohring, V. Sahakian, M. Samorski, D. Schmele, F. Schroder, W. Stamm, B. Wiebel-Sooth, C. Wiedner, M. Willmer, H. Wirth, W. Wittek

Ref:1999A&A...349...29A.

Energy Spectrum and Chemical Composition of Cosmic Rays between 0.3 and 10 PeV determined from the Cherenkov-Light and Charged-Particle distribution in Air Showers.

F. Aharonian, A.G. Akhperjanian, F.Arqueros, J.A. Barrio, K. Bernlohr, H. Bojahr, I. Calle, J.L. Contreras, J. Cortina, A. Daum, T. Deckers, S. Denninghoff, V. Fonseca, J. Gebauer, J.C. Gonzalez, G. Heinzelmann, M. Hemberger, G. Hermann, M. Hess, A. Heusler, W. Hofmann, H. Hohl, D. Horns, A. Ibarra, R. Kankanyan, M. Kestel, O. Kirstein, C. Kohler, H. Kornmayer, D. Kranich, H. Krawczynski, H. Lampeitl, A. Lindner, E. Lorenz, N. Magnussen, H. Meyer, R. Mirzoyan, A. Moralejo, L. Padilla, M. Panter, D. Petry, R. Plaga, A. Plyasheshnikov, J. Prahl, G. Puhlhofer, G. Rauterberg, C. Renault, W. Rhode, A. Rohring, V. Sahakian, M. Samorski, D. Schmele, F. Schroder, W. Stamm, H. Volk, B. Wiebel-Sooth, C. Wiedner, M. Willmer, H. Wirth, W. Wittek

Ref:2000A&A...359..682H.

Observations of Mkn 421 during 1997 and 1998 in the energy range above 500 GeV with HEGRA stereoscopic Cherenkov telescope system

F. Aharonian, A.G. Akhperjanian, J.A. Barrio, K. Bernlohr, H. Bojahr, I. Calle, J.L. Contreras, J. Cortina, A. Daum, T. Deckers, S. Denninghoff, V. Fonseca, J. Gebauer, J.C. Gonzalez, G. Heinzelmann, M. Hemberger, G. Hermann, M. Hess, A. Heusler, W. Hofmann, H. Hohl, D. Horns, A. Ibarra, R. Kankanyan, M. Kestel, O. Kirstein, C. Kohler, H. Kornmayer, D. Kranich, H. Krawczynski, H. Lampeitl, A. Lindner, E. Lorenz, N. Magnussen, H. Meyer, R. Mirzoyan, A. Moralejo, L. Padilla, M. Panter, D. Petry, R. Plaga, A. Plyasheshnikov, J. Prahl, G. Puhlhofer, G. Rauterberg, C. Renault, W. Rhode, A. Rohring, V. Sahakian, M. Samorski, D. Schmele, F. Schroder, W. Stamm, H. Volk, B. Wiebel-Sooth, C. Wiedner, M. Willmer, H. Wirth, W. Wittek

Ref:1999A&A...350..757A.

Constrains on BL Lac objects by the HEGRA-system of Cherenkov telescopes.

F. Aharonian, A.G. Akhperjanian, J.A. Barrio, K. Bernlohr, H. Bojahr, I. Calle, J.L. Contreras, J. Cortina, A. Daum, T. Deckers, S. Denninghoff, V. Fonseca, J. Gebauer, J.C. Gonzalez, G. Heinzelmann, M. Hemberger, G. Hermann, M. Hess, A. Heusler, W. Hofmann, H. Hohl, D. Horns, A. Ibarra, R. Kankanyan, M. Kestel, O. Kirstein, C. Kohler, H. Kornmayer, D. Kranich, H. Krawczynski, H. Lampeitl, A. Lindner, E. Lorenz, N. Magnussen, H. Meyer, R. Mirzoyan, A. Moralejo, L. Padilla, M. Panter, D. Petry, R. Plaga, A. Plyasheshnikov, J. Prahl, G. Puhlhofer, G. Rauterberg, C. Renault, W. Rhode, A. Rohring, V. Sahakian, M. Samorski, D. Schmele, F. Schroder, W. Stamm, H. Volk, B. Wiebel-Sooth, C. Wiedner, M. Willmer, H. Wirth, W. Wittek

Ref:A&A (?)

HEGRA search for TeV emission from BL Lac objects.

F. Aharonian, A.G. Akhperjanian, J.A. Barrio, K. Bernlohr, H. Bojahr, I. Calle, J.L. Contreras, J. Cortina, A. Daum, T. Deckers, S. Denninghoff, V. Fonseca, J.C. Gonzalez, G. Heinzelmann, M. Hemberger, G. Hermann, M. Heb, A. Heusler, W. Hofmann, H. Hohl, D. Horns, A. Ibarra, R. Kankanyan, J. Kettler, C. Kohler, A. Konopelko, H. Kornmayer, D. Kranich, H. Krawczynski, H. Lampeitl, A. Lindner, E. Lorenz, N. Magnussen, H. Meyer, R. Mirzoyan, A. Moralejo, L. Padilla, M. Panter, D. Petry, R. Plaga, A. Plyasheshnikov, J. Prahl, G. Puhlhofer, G. Rauterberg, C. Renault, W. Rhode, A. Rohring, V. Sahakian, M. Samorski, D. Schmele, F. Schroder, W. Stamm, H. Volk, B. Wiebel-Sooth, C. Wiedner, M. Willmer, W. Wittek

Ref:2000A&A...353..847A

The Energy of TeV Gamma-Rays from the Crab Nebula as measured by the HEGRA system of imaging air Cherenkov telescopes.

F. Aharonian, A.G. Akhperjanian, J.A. Barrio, K. Bernlohr, H. Bojahr, I. Calle, J.L. Contreras, J. Cortina, A. Daum, T. Deckers, S. Denninghoff, V. Fonseca, J. Gebauer, J.C. Gonzalez, G. Heinzelmann, M. Hemberger, G. Hermann, M. Hess, A. Heusler, W. Hofmann, H. Hohl, D. Horns, A. Ibarra, R. Kankanyan, M. Kestel, O. Kirstein, C. Kohler, H. Kornmayer, D. Kranich, H. Krawczynski, H. Lampeitl, A. Lindner, E. Lorenz, N. Magnussen, H. Meyer, R. Mirzoyan, A. Moralejo, L. Padilla, M. Panter, D. Petry, R. Plaga, A. Plyasheshnikov, J. Prahl, G. Puhlhofer, G. Rauterberg, C. Renault, W. Rhode, A. Rohring, V. Sahakian, M. Samorski, D. Schmele, F. Schroder, W. Stamm, H. Volk, B. Wiebel-Sooth, C. Wiedner, M. Willmer, W. Wittek

Ref:2000ApJ...539..317A

An experimental limit on the size of the emission region for VHE gamma rays in the Crab Nebula.

F. Aharonian, A.G. Akhperjanian, J.A. Barrio, K. Bernlohr, H. Bojahr, I. Calle, J.L. Contreras, J. Cortina, A. Daum, T. Deckers, S. Denninghoff, V. Fonseca, J.C. Gonzalez, N. Gotting, G. Heinzelmann, M. Hemberger, G. Hermann, M. Hess, A. Heusler, W. Hofmann, H. Hohl, D. Horns, A. Ibarra, R. Kankanyan, J. Kettle, C. Kohler, A. Konpelko, H. Kornmayer, M. Kestel, D. Kranich, H. Krawczynski, H. Lampeitl, A. Lindner, E. Lorenz, N. Magnussen, O. Mang, H. Meyer, R. Mirzoyan, A. Moralejo, L. Padilla, M. Panter, D. Petry, R. Plaga, A. Plyasheshnikov, J. Prahl, G. Puhlhofer, G. Rauterberg, C. Renault, W. Rhode, A. Rohring, V. Sahakian, M. Samorski, M. Schilling, F. Schroder, W. Stamm, M. Tluczykont, H. Volk, B. Wiebel-Sooth, C. Wiedner, M. Willmer, W. Wittek

Ref: A&A (?)

Cosmic Ray Proton Spectrum determined with the Imaging Atmospheric Cherenkov Technique.

F. Aharonian, A. G. Akhperjanian, J. A. Barrio, A. S. Belgarian, K. Bernlohr, J. J. G. Beteta, H. Bojahr, S. Bradbury, I. Calle, J. L. Contreras, J. Cortina, A. Daum, T. Deckers, S. Denninghoff, V. Fonseca, J. C. Gonzalez, G. Heinzelmann, M. Hemberger, G. Hermann, M. Hess, A. Heusler, W. Hofmann, H. Hohl, I. Holl, D. Horns, A. Ibarra, R. Kankanyan, M. Kestel, O. Kirstein, C. Kohler, A. Konopelko, H. Kornmeyer, D. Kranich, H. Krawczynski, H. Lampeitl, A. Lindner, E. Lorenz, N. Magnussen, H. Meyer, R. Mirzoyan, A. Moralejo, L. Padilla, M. Panter, D. Petry, R. Plaga, A. Plyasheshnikov, J. Prahl, C. Prosch, G. Puhlhofer, G. Rauterberg, C. Renault, W. Rhode, A. Rohring, V. Sahakian, M. Samorski, D. Schmele, F. Schroder, W. Stamm, H. J. Volk, B. Wiebel-Sooth, C. A. Wiedner, M. Willmer, and H. Wirth

Ref: Phys. Rev. D 59, 092003 (1999)

WHIPPLE

[6~
Cutoff in the TeV Energy Spectrum of Markarian 421 During Strong Flares in 2001

F. Krennrich, H.M. Badran, I.H. Bond, S.M. Bradbury, J.H. Buckley, D.A. Carter-Lewis, M. Catanese, W. Cui, S. Dunlea, D. Das, I. de la Calle Perez, 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, D. Horan, M. Jordan, M. Kertzman, D. Kieda, J. Kildea, J. Knapp, K. Kosack, M.J. Lang, S. LeBohec, B. McKernan, P. Moriarty, D. Müller, 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, T.C. Weekes

Ref: Accepted in ApJL (2001)

Detection of the BL Lac Object 1H1426+428 at TeV Gamma Ray Energies.

D. Horan, H.M. Badran, I.H. Bond, S.M. Bradbury, J.H. Buckley, D.A. Carter-Lewis, M. Catanese, W. Cui, S. Dunlea, D. Das, I. de la Calle Perez, 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, D. Horan, M. Jordan, M. Kertzman, D. Kieda, J. Kildea, J. Knapp, K. Kosack, M.J. Lang, S. LeBohec, B. McKernan, P. Moriarty, D. M|ller, 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, T.C. Weekes

Ref: Accepted in ApJ (2002)

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