Most cited MAGIC and KASCADE papers



TITLE


KASCADE measurements of energy spectra for elemental groups of cosmic rays: Results and open problems

Authors

Tea Antoni, WD Apel, AF Badea, K Bekk, A Bercuci, J Blümer, H Bozdog, IM Brancus, A Chilingarian, K Daumiller, P Doll, R Engel, J Engler, F Feßler, HJ Gils, R Glasstetter, A Haungs, D Heck, JR Hörandel, K-H Kampert, HO Klages, G Maier, HJ Mathes, HJ Mayer, J Milke, M Müller, R Obenland, J Oehlschläger, S Ostapchenko, M Petcu, H Rebel, A Risse, M Risse, M Roth, G Schatz, H Schieler, J Scholz, T Thouw, Holger Ulrich, J Van Buren, A Vardanyan, A Weindl, J Wochele, J Zabierowski

Publication date

2005/9/1

Journal

Astroparticle physics

Volume

24

Issue

1-2

Pages

1-25

Publisher

North-Holland

Description

A composition analysis of KASCADE air shower data is performed by means of unfolding the two-dimensional frequency spectrum of electron and muon numbers. Aim of the analysis is the determination of energy spectra for elemental groups representing the chemical composition of primary cosmic rays. Since such an analysis depends crucially on simulations of air showers the two different hadronic interaction models QGSJet and SIBYLL are used for their generation. The resulting primary energy spectra show that the knee in the all particle spectrum is due to a steepening of the spectra of light elements but, also, that neither of the two simulation sets is able to describe the measured data consistently over the whole energy range with discrepancies appearing in different energy regions.

Total citations

Cited by 723

 

Very-high-energy gamma rays from a distant quasar: how transparent is the universe?

Authors

Jord Albert, E Aliu, H Anderhub, LA Antonelli, P Antoranz, M Backes, C Baixeras, JA Barrio, H Bartko, D Bastieri, JK Becker, W Bednarek, K Berger, E Bernardini, C Bigongiari, A Biland, RK Bock, G Bonnoli, P Bordas, V Bosch-Ramon, T Bretz, I Britvitch, M Camara, E Carmona, A Chilingarian, S Commichau, JL Contreras, J Cortina, MT Costado, S Covino, V Curtef, F Dazzi, A De Angelis, E De Cea Del Pozo, R de Los Reyes, B De Lotto, M De Maria, F De Sabata, C Delgado Mendez, A Dominguez, D Dorner, M Doro, M Errando, M Fagiolini, D Ferenc, E Fernández, R Firpo, MV Fonseca, L Font, N Galante, RJ García López, M Garczarczyk, M Gaug, F Goebel, M Hayashida, A Herrero, D Höhne, J Hose, CC Hsu, S Huber, T Jogler, TM Kneiske, D Kranich, A La Barbera, A Laille, E Leonardo, E Lindfors, S Lombardi, F Longo, M López, E Lorenz, P Majumdar, G Maneva, N Mankuzhiyil, K Mannheim, L Maraschi, M Mariotti, M Martínez, D Mazin, M Meucci, M Meyer, JM Miranda, R Mirzoyan, S Mizobuchi, M Moles, A Moralejo, D Nieto, K Nilsson, J Ninkovic, N Otte, I Oya, M Panniello, R Paoletti, JM Paredes, M Pasanen, D Pascoli, F Pauss, RG Pegna, MA Perez-Torres, M Persic, L Peruzzo, A Piccioli, F Prada, E Prandini, N Puchades, A Raymers, W Rhode, M Ribó, J Rico, M Rissi, A Robert, S Rügamer, A Saggion, TY Saito, M Salvati, M Sanchez-Conde, P Sartori, K Satalecka, V Scalzotto, V Scapin, R Schmitt, T Schweizer, M Shayduk, K Shinozaki, SN Shore, N Sidro, A Sierpowska-Bartosik, A Sillanpää, D Sobczynska, F Spanier, A Stamerra, LS Stark, L Takalo, F Tavecchio, P Temnikov, D Tescaro, M Teshima, M Tluczykont, DF Torres, N Turini, H Vankov, A Venturini, V Vitale, RM Wagner, W Wittek, V Zabalza, F Zandanel, R Zanin, J Zapatero

Publication date

2008/6/27

Journal

Science

Volume

320

Issue

5884

Pages

1752-1754

Publisher

American Association for the Advancement of Science

Description

The atmospheric Cherenkov gamma-ray telescope MAGIC, designed for a low-energy threshold, has detected very-high-energy gamma rays from a giant flare of the distant Quasi-Stellar Radio Source (in short: radio quasar) 3C 279, at a distance of more than 5 billion light-years (a redshift of 0.536). No quasar has been observed previously in very-high-energy gamma radiation, and this is also the most distant object detected emitting gamma rays above 50 gigaelectron volts. Because high-energy gamma rays may be stopped by interacting with the diffuse background light in the universe, the observations by MAGIC imply a low amount for such light, consistent with that known from galaxy counts.

Total citations

Cited by 562

 

Observation of gamma rays from the galactic center with the MAGIC telescope

Authors

J Albert, E Aliu, H Anderhub, P Antoranz, A Armada, M Asensio, C Baixeras, JA Barrio, M Bartelt, H Bartko, D Bastieri, R Bavikadi, W Bednarek, K Berger, C Bigongiari, A Biland, E Bisesi, RK Bock, T Bretz, I Britvitch, M Camara, A Chilingarian, S Ciprini, JA Coarasa, S Commichau, JL Contreras, J Cortina, V Curtef, V Danielyan, F Dazzi, A De Angelis, R De los Reyes, B De Lotto, E Domingo-Santamaría, D Dorner, M Doro, M Errando, M Fagiolini, D Ferenc, E Fernández, R Firpo, J Flix, MV Fonseca, L Font, N Galante, M Garczarczyk, M Gaug, M Giller, F Goebel, D Hakobyan, M Hayashida, T Hengstebeck, D Höhne, J Hose, P Jacon, O Kalekin, D Kranich, A Laille, T Lenisa, P Liebing, E Lindfors, F Longo, J López, M López, E Lorenz, F Lucarelli, P Majumdar, G Maneva, K Mannheim, M Mariotti, M Martínez, K Mase, D Mazin, M Merck, M Meucci, M Meyer, JM Miranda, R Mirzoyan, S Mizobuchi, A Moralejo, K Nilsson, E Oña-Wilhelmi, R Orduña, N Otte, I Oya, D Paneque, R Paoletti, M Pasanen, D Pascoli, F Pauss, N Pavel, R Pegna, L Peruzzo, A Piccioli, E Prandini, J Rico, W Rhode, B Riegel, M Rissi, A Robert, S Rügamer, A Saggion, A Sánchez, P Sartori, V Scalzotto, R Schmitt, T Schweizer, M Shayduk, K Shinozaki, Steven Neil Shore, N Sidro, A Sillanpää, D Sobczynska, A Stamerra, A Stepanian, LS Stark, L Takalo, P Temnikov, D Tescaro, M Teshima, N Tonello, A Torres, DF Torres, N Turini, H Vankov, A Vardanyan, V Vitale, RM Wagner, T Wibig, W Wittek, J Zapatero

Publication date

2006/1/25

Journal

The Astrophysical Journal Letters

Volume

638

Issue

2

Pages

L101

Publisher

IOP Publishing

Description

Recently, the Galactic center has been reported to be a source of very high energy (VHE) γ‐rays by the CANGAROO, VERITAS, and HESS experiments. The energy spectra as measured by these experiments show substantial differences. In this Letter we present MAGIC observations of the Galactic center, resulting in the detection of a differential γ‐ray flux consistent with a steady, hard‐slope power law, described as cm−2 s−1 TeV−1. The γ‐ray source is centered at (R.A., decl.) = (17h45m20s, −29°2 ). This result confirms the previous measurements by the HESS experiment and indicates a steady source of TeV γ‐rays. We briefly describe the observational technique used and the procedure implemented for the data analysis, and we discuss the results in the perspective of different models proposed for the acceleration of the VHE γ‐rays.

Total citations

Cited by 282

 

Very high energy gamma-ray radiation from the stellar mass black hole binary Cygnus X-1

Authors

J Albert, E Aliu, H Anderhub, P Antoranz, A Armada, C Baixeras, JA Barrio, H Bartko, D Bastieri, JK Becker, W Bednarek, K Berger, C Bigongiari, A Biland, RK Bock, P Bordas, V Bosch-Ramon, T Bretz, I Britvitch, M Camara, E Carmona, A Chilingarian, JA Coarasa, S Commichau, JL Contreras, J Cortina, MT Costado, V Curtef, V Danielyan, F Dazzi, A De Angelis, C Delgado, R De Los Reyes, B De Lotto, E Domingo-Santamaría, D Dorner, M Doro, M Errando, M Fagiolini, D Ferenc, E Fernández, R Firpo, J Flix, MV Fonseca, L Font, M Fuchs, N Galante, RJ García-López, M Garczarczyk, M Gaug, M Giller, F Goebel, D Hakobyan, M Hayashida, T Hengstebeck, A Herrero, D Höhne, J Hose, CC Hsu, P Jacon, T Jogler, R Kosyra, D Kranich, R Kritzer, A Laille, E Lindfors, S Lombardi, Francesco Longo, J López, M López, E Lorenz, P Majumdar, G Maneva, K Mannheim, O Mansutti, M Mariotti, M Martínez, D Mazin, C Merck, M Meucci, M Meyer, JM Miranda, R Mirzoyan, S Mizobuchi, A Moralejo, D Nieto, K Nilsson, J Ninkovic, E Oña-Wilhelmi, N Otte, I Oya, M Panniello, R Paoletti, JM Paredes, M Pasanen, D Pascoli, F Pauss, R Pegna, M Persic, L Peruzzo, A Piccioli, E Prandini, N Puchades, A Raymers, W Rhode, M Ribó, J Rico, M Rissi, A Robert, S Rügamer, A Saggion, T Saito, A Sánchez, P Sartori, V Scalzotto, V Scapin, R Schmitt, T Schweizer, M Shayduk, K Shinozaki, Steven Neil Shore, N Sidro, A Sillanpää, D Sobczynska, A Stamerra, LS Stark, L Takalo, P Temnikov, D Tescaro, M Teshima, DF Torres, N Turini, H Vankov, V Vitale, RM Wagner, T Wibig, W Wittek, F Zandanel, R Zanin, J Zapatero

Publication date

2007/7/31

Journal

The Astrophysical Journal Letters

Volume

665

Issue

1

Pages

L51

Publisher

IOP Publishing

Description

We report on the results from the observations in the very high energy band (VHE; GeV) of the black hole Xray binary (BHXB) Cygnus X1. The observations were performed with the MAGIC telescope, for a total of 40 hr during 26 nights, spanning the period between 2006 June and November. Searches for steady γray signals yielded no positive result, and upper limits to the integral flux ranging between 1% and 2% of the Crab Nebula flux, depending on the energy, have been established. We also analyzed each observation night independently, obtaining evidence of γray signals at the 4.0 σ significance level (3.2 σ after trial correction) for 154 minutes of effective ontime (EOT) on September 24 between 20:58 and 23:41 UTC, coinciding with an Xray flare seen by RXTESwift, and INTEGRAL. A search for fastervarying signals within a night resulted in an excess with a significance of 4.9 σ (4.1 σ after trial …

Total citations

Cited by 380

 

Methods for multidimensional event classification: a case study using images from a Cherenkov gamma-ray telescope

Authors

RK Bock, A Chilingarian, M Gaug, F Hakl, Th Hengstebeck, M Jiřina, J Klaschka, E Kotrč, P Savický, S Towers, A Vaiciulis, W Wittek

Publication date

2004/1/11

Journal

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

Volume

516

Issue

2-3

Pages

511-528

Publisher

North-Holland

Description

We present results from a case study comparing different multivariate classification methods. The input is a set of Monte Carlo data, generated and approximately triggered and pre-processed for an imaging gamma-ray Cherenkov telescope. Such data belong to two classes, originating either from incident gamma rays or caused by hadronic showers. There is only a weak discrimination between signal (gamma) and background (hadrons), making the data an excellent proving ground for classification techniques.

The data and methods are described, and a comparison of the results is made. Several methods give results comparable in quality within small fluctuations, suggesting that they perform at or close to the Bayesian limit of achievable separation. Other methods give clearly inferior or inconclusive results. Some problems that this study can not address are also discussed.

Total citations

Cited by 259

 

Electron, muon, and hadron lateral distributions measured in air showers by the KASCADE experiment

Authors

T Antoni, WD Apel, F Badea, K Bekk, K Bernlöhr, H Blümer, E Bollmann, H Bozdog, IM Brancus, A Chilingarian, K Daumiller, P Doll, J Engler, F Fessler, HJ Gils, R Glasstetter, R Haeusler, W Hafemann, A Haungs, D Heck, T Holst, JR Hörandel, K-H Kampert, J Kempa, HO Klages, J Knapp, D Martello, HJ Mathes, HJ Mayer, J Milke, D Mühlenberg, J Oehlschläger, M Petcu, H Rebel, M Risse, M Roth, G Schatz, FK Schmidt, T Thouw, H Ulrich, A Vardanyan, B Vulpescu, JH Weber, J Wentz, T Wiegert, J Wochele, J Zabierowski, KASCADE Collaboration

Publication date

2001/1/1

Journal

Astroparticle Physics

Volume

14

Issue

4

Pages

245-260

Publisher

North-Holland

Description

Measurements of electron, muon and hadron lateral distributions of extensive air showers as recorded in the Karlsruhe shower core and array detector experiment are presented. The data cover the energy range from 5×1014 eV up to almost 1017 eV and extend from the inner core region to distances of 200 m. The electron and muon distributions are corrected for mutual contaminations by taking into account the detector properties in the experiment. All distributions are well described by NKG functions. The scale radii describing the electron and hadron data best are 30 and 10 m, respectively. We discuss the correlation between the scale radii and the `age' parameter as well as their dependence on shower size, zenith angle, and particle energy threshold.

Total citations

Cited by 199