1. Performance of the MAGIC telescopes under moonlight
- Author
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L. Maraschi, Elina Lindfors, Daniel Mazin, S. Schroeder, Ivica Puljak, U. Menzel, Alexander Hahn, Gareth Hughes, Pierre Colin, M. Doert, M. Vazquez Acosta, E. de Oña Wilhelmi, D. Dominis Prester, Diego F. Torres, J. Palacio, B. Biasuzzi, J. M. Paredes, M. Garczarczyk, Victoria Moreno, V. Fallah Ramazani, S. Paiano, Antonio Stamerra, Stefano Covino, L. Nogués, Karl Mannheim, D. Ninci, A. Niedzwiecki, Kazuma Ishio, A. De Angelis, U. Barres de Almeida, A. Treves, Vitaly Neustroev, R. J. García López, E. Moretti, Damir Lelas, Abelardo Moralejo, Christian Fruck, Dario Hrupec, David Paneque, Dorota Sobczyńska, Francesco Longo, J. Becerra González, Ievgen Vovk, Mosè Mariotti, M. A. Lopez, G. Maneva, Adrian Biland, B. Banerjee, C. Arcaro, G. Pedaletti, T. Surić, J. R. Garcia, E. Prandini, Max Ludwig Ahnen, Louis Antonelli, D. Guberman, Marina Manganaro, Alessio Berti, Aaron Dominguez, M. I. Martínez, Ana Babić, Tomoki Saito, D. Tescaro, J. Kushida, T. Schweizer, P. Temnikov, D. Galindo, J. Rico, Massimo Persic, Arka Chatterjee, M. Minev, I. Reichardt, P. Cumani, Jose Luis Contreras, Konstancja Satalecka, Sabrina Einecke, Michele Doro, Juan Cortina, P. Giammaria, D. Kuveždić, Martin Makariev, J. E. Ward, D. Fidalgo, Giacomo Bonnoli, Julian Sitarek, Rodolfo Carosi, M. Hayashida, Saverio Lombardi, Oscar Blanch, Kyoshi Nishijima, B. De Lotto, L. Perri, J. Hose, Wolfgang Rhode, I. Snidaric, Wrijupan Bhattacharyya, Andrea Rugliancich, Yusuke Konno, D. Zarić, D. Eisenacher Glawion, Marc Ribó, Nikola Godinovic, X. Paredes-Fortuny, D. Elsaesser, Marcel Strzys, M. Nievas Rosillo, P. Bangale, D. Hadasch, Daniela Dorner, F. Di Pierro, Hidetoshi Kubo, Stefano Ansoldi, Riccardo Paoletti, Kari Nilsson, Dariusz Gora, Gaia Vanzo, M. Will, Wlodek Bednarek, Alessandro Carosi, N. Torres-Albà, M. Gaug, P. Da Vela, A. Sillanpää, E. Colombo, J. Herrera, L. O. Takalo, Koji Noda, S. Bonnefoy, Elisa Bernardini, M. Engelkemeier, Tarek M. Hassan, Camilla Maggio, R. Mirzoyan, S. Griffiths, Masahiro Teshima, Fabrizio Tavecchio, Ll. Font, Tomislav Terzić, Juan Abel Barrio, Francesco Dazzi, A. Fernández-Barral, Pratik Majumdar, M. V. Fonseca, M. Peresano, P. G. Prada Moroni, Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Arcaro, C., Babiä , A., Banerjee, B., Bangale, P., Barres de Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Berti, Alessio, Bhattacharyya, W., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Carosi, R., Carosi, A., Chatterjee, A., Colin, P, Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., de Oña Wilhelmi, E., Di Pierro, F., Doert, M., Domãnguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Eisenacher Glawion, D., Elsaesser, D., Engelkemeier, M., Fallah Ramazani, V., Fernández Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., GarcÃa López, R. J., Garczarczyk, M., Gaug, M., Giammaria, P., Godinoviä , N., Gora, D., Griffiths, S., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Hughes, G., Ishio, K., Konno, Y., Kubo, H., Kushida, J., Kuveå¾diä , D., Lelas, D., Lindfors, E., Lombardi, S., Longo, Francesco, Lã³pez, M., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martãnez, M., Mazin, D., Menzel, U., Minev, M., Mirzoyan, R., Moralejo, A., Moreno, V., Moretti, E., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Noguã©s, L., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Paredes Fortuny, X., Pedaletti, G., Peresano, M., Perri, L., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Garcia, J. R., Reichardt, I., Rhode, W., Ribã³, M., Rico, J., Rugliancich, A., Saito, T., Satalecka, K., Schroeder, S., Schweizer, T., Sillanpã¤ã¤, A., Sitarek, J., Å nidariä , I., Sobczynska, D., Stamerra, A., Strzys, M., Suriä , T., Takalo, L., Tavecchio, F., Temnikov, P., Terziä , T., Tescaro, D., Teshima, M., Torres, D. F., Torres Albà , N., Treves, A., Vanzo, G., Vazquez Acosta, M., Vovk, I., Ward, J. E., Will, M., and Zariä , D.
- Subjects
Moonlight ,Photomultiplier ,Twilight ,media_common.quotation_subject ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astrophysics ,Cherenkov telescopes ,01 natural sciences ,Gamma-ray astronomy ,Crab Nebula ,Optics ,0103 physical sciences ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,010303 astronomy & astrophysics ,Cherenkov radiation ,media_common ,Physics ,ta115 ,010308 nuclear & particles physics ,business.industry ,Crab nebula ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astronomy and Astrophysics ,Cherenkov telescope ,Sky ,Duty cycle ,ddc:540 ,Electrónica ,Física nuclear ,Electricidad ,business ,Astrophysics - Instrumentation and Methods for Astrophysics - Abstract
MAGIC, a system of two imaging atmospheric Cherenkov telescopes, achieves its best performance under dark conditions, i.e. in absence of moonlight or twilight. Since operating the telescopes only during dark time would severely limit the duty cycle, observations are also performed when the Moon is present in the sky. Here we develop a dedicated Moon-adapted analysis to characterize the performance of MAGIC under moonlight. We evaluate energy threshold, angular resolution and sensitivity of MAGIC under different background light levels, based on Crab Nebula observations and tuned Monte Carlo simulations. This study includes observations taken under non-standard hardware configurations, such as reducing the camera photomultiplier tubes gain by a factor ~1.7 (Reduced HV settings) with respect to standard settings (Nominal HV) or using UV-pass filters to strongly reduce the amount of moonlight reaching the cameras of the telescopes. The Crab Nebula spectrum is correctly reconstructed in all the studied illumination levels, that reach up to 30 times brighter than under dark conditions. The main effect of moonlight is an increase in the analysis energy threshold and in the systematic uncertainties on the flux normalization. The sensitivity degradation is constrained to be below 10%, within 15-30% and between 60 and 80% for Nominal HV, Reduced HV and UV-pass filter observations, respectively. No worsening of the angular resolution was found. Thanks to observations during moonlight, the maximal duty cycle of MAGIC can be increased from ~18%, under dark nights only, to up to ~40% in total with only moderate performance degradation., 14 pages, 13 figures, accepted in Astroparticle Physics. Corresponding authors: Daniel Guberman (dguberman@ifae.es) and Pierre Colin (colin@mppmu.mpg.de)
- Published
- 2017