443 research outputs found
Erratum: Search for photons with energies above 1018 eV using the hybrid detector of the Pierre Auger Observatory (Journal of Cosmology and Astroparticle Physics (2017) 4 (9) DOI: 10.1088/1475-7516/2017/04/009)
No full text1 Exposure calculation Due to a mistake in the numerical integration following eq. (6.2) of the original article [1], the exposure shown in figure 5 of the original article was incorrect. The correct exposure is shown in figure 1. 2 Upper limits on the integral photon flux and fraction The incorrect exposure affects the calculation of the upper limits on the integral photon flux following eq. (6.1) of the original article. The correct values for the upper limits are 0.038, 0.010, 0.009, 0.008 and 0.007 km−2 sr−1 yr−1 for threshold energies of 1, 2, 3, 5 and 10 EeV. The correct values for the upper limits on the integral photon fraction subsequently derived are 0.14 %, 0.17 %, 0.42 %, 0.86 % and 2.9 % for the same threshold energies. 3 Author list The author list of this erratum also corrects a mistake made in the original article, where F. Zuccarello was missing and Z. Zong was listed twice
Erratum: Search for photons with energies above 1018 eV using the hybrid detector of the Pierre Auger Observatory
No full textExposure calculation Due to a mistake in the numerical integration following eq. (6.2) of the original article [1], the exposure shown in figure 5 of the original article was incorrect. The correct exposure is shown in figure 1. 2 Upper limits on the integral photon flux and fraction The incorrect exposure affects the calculation of the upper limits on the integral photon flux following eq. (6.1) of the original article. The correct values for the upper limits are 0.038, 0.010, 0.009, 0.008 and 0.007 km−2 sr−1 yr−1 for threshold energies of 1, 2, 3, 5 and 10 EeV. The correct values for the upper limits on the integral photon fraction subsequently derived are 0.14 %, 0.17 %, 0.42 %, 0.86 % and 2.9 % for the same threshold energies. 3 Author list The author list of this erratum also corrects a mistake made in the original article, where F. Zuccarello was missing and Z. Zong was listed twice
A 3-Year Sample of Almost 1,600 Elves Recorded Above South America by the Pierre Auger Cosmic-Ray Observatory
No full textElves are a class of transient luminous events, with a radial extent typically greater than 250 km, that occur in the lower ionosphere above strong electrical storms.We report the observation of 1,598 elves, from 2014 to 2016, recorded with unprecedented time resolution (100 ns) using the fluorescence detector (FD) of the Pierre Auger Cosmic-Ray Observatory. The Auger Observatory is located in the Mendoza province of Argentina with a viewing footprint for elve observations of 3 · 106 km2, reaching areas above the Pacific and Atlantic Oceans, as well as the Córdoba region, which is known for severe convective thunderstorms. Primarily designed for ultrahigh energy cosmic-ray observations, the Auger FD turns out to be very sensitive to the ultraviolet emission in elves. The detector features modified Schmidt optics with large apertures resulting in a field of view that spans the horizon, and year-round operation on dark nights with low moonlight background, when the local weather is favorable. The measured light profiles of 18% of the elve events have more than one peak, compatible with intracloud activity. Within the 3-year sample, 72% of the elves correlate with the far-field radiation measurements of the World Wide Lightning Location Network. The Auger Observatory plans to continue operations until at least 2025, including elve observations and analysis. To the best of our knowledge, this observatory is the only facility on Earth that measures elves with year-round operation and full horizon coverage.
Co-authors: A. Aab, P. Abreu,M. Aglietta, I. F.M. Albuquerque, J.M. Albury, I. Allekotte, A. Almela, J. Alvarez Castillo, J. Alvarez-Muniz, G. A. Anastasi,L. Anchordoqui, B. Andrada, S. Andringa, C. Aramo, H. Asorey, P. Assis, G. Avila, A.M. Badescu, A. Bakalova, A. Balaceanu,F. Barbato, R. J. Barreira Luz, S. Baur, K. H. Becker, J.A. Bellido, C. Berat,M. E. Bertaina, X. Bertou, P. L. Biermann, J. Biteau, S. G. Blaess, A. Blanco, J. Blazek, C. Bleve,M. Bohaˇcova, D. Boncioli, C. Bonifazi, N. Borodai, A. M. Botti, J. Brack,T. Bretz, A. Bridgeman, F. L. Briechle, P. Buchholz, A. Bueno, S. Buitink,M. Buscemi, K. S. Caballero-Mora, L. Caccianiga, L. Calcagni, A. Cancio, F. Canfora, J.M. Carceller, R. Caruso, A. Castellina, F. Catalani, G. Cataldi, L. Cazon,M. Cerda, J. A. Chinellato,J. Chudoba, L. Chytka, R.W. Clay, A. C. Cobos Cerutti, R. Colalillo, A. Coleman,M. R. Coluccia, R. Conceicao, A. Condorelli, G. Consolati,F. Contreras,M. J. Cooper, S. Coutu, C. E. Covault, B. Daniel, S. Dasso, K. Daumiller, B. R. Dawson, J. A. Day, R.M. de Almeida,S. J. de Jong, G. Mauro, J. R. T. de Mello Neto, I. Mitri, J. de Oliveira, F. O. de Oliveira Salles, V. de Souza, J. Debatin,M. del Rio, O. Deligny,N. Dhital,M. L. Diaz Castro, F. Diogo, C. Dobrigkeit, J. C. D\u27Olivo, Q. Dorosti, R. C. dos Anjos, M. T. Dova, A. Dundovic, J. Ebr, R. Engel,M. Erdmann, C. O. Escobar, A. Etchegoyen, H. Falcke, J. Farmer, G. Farrar, A. C. Fauth, N. Fazzini, F. Feldbusch,F. Fenu, L. P. Ferreyro, J.M. Figueira, A. Filipˇciˇc, M. M. Freire, T. Fujii, A. Fuster, B. Garcia, H. Gemmeke, A. Gherghel-Lascu,P. L. Ghia, U. Giaccari,M. Giammarchi,M. Giller, D. Głas, J. Glombitza, F. Gobbi, G. Golup,M. Gomez Berisso, P. F. Gomez Vitale,J. P. Gongora, N. Gonzalez, I. Goos, D. Gora, A. Gorgi,M. Gottowik, T. D. Grubb, F. Guarino, G. P. Guedes, E. Guido,R. Halliday, M. R. Hampel, P. Hansen, D. Harari, T. A. Harrison, V. M. Harvey, A. Haungs, T. Hebbeker, D. Heck, P. Heimann,G. C. Hill, C. Hojvat, E. M. Holt, P. Homola, J. R. Horandel, P. Horvath,M. Hrabovsky, T. Huege, J. Hulsman, A. Insolia,P. G. Isar, I. Jandt, J. A. Johnsen,M. Josebachuili, J. Jurysek, A. Kaapa, K. H. Kampert, B. Keilhauer, N. Kemmerich, J. Kemp,H. O. Klages, M. Kleifges, J. Kleinfeller, R. Krause, D. Kuempel, G. Kukec Mezek, A. Kuotb Awad, B. L. Lago, D. LaHurd, R. G. Lang,R. Legumina,M. A. Leigui de Oliveira, V. Lenok, A. Letessier-Selvon, I. Lhenry-Yvon, O. C. Lippmann, D. Lo Presti, L. Lopes, R. Lopez, A. Lopez Casado,R. Lorek, Q. Luce, A. Lucero,M. Malacari, G. Mancarella, D. Mandat, B. C. Manning, P. Mantsch, A. G. Mariazzi, I. C. Mari，s, G. Marsella, D. Martello, H. Martinez, O. Martinez Bravo,M. Mastrodicasa, H. J. Mathes, S. Mathys, J. Matthews, G. Matthiae, E. Mayotte,P. O. Mazur, G. Medina-Tanco, D. Melo, A. Menshikov, K.-D. Merenda, S. Michal,M. I. Micheletti, L. Middendorf, L. Miramonti, B. Mitrica,D. Mockler, S. Mollerach, F. Montanet, C. Morello, G. Morlino,M. Mostafa, A. L. Muller,M. A. Muller, S. Muller, R. Mussa,L. Nellen, P. H. Nguyen,M. Niculescu-Oglinzanu,M. Niechciol, D. Nitz, D. Nosek, V. Novotny, L. Noža, A Nucita, L.A. Nunez,A. Olinto,M. Palatka, J. Pallotta,M. P. Panetta, P. Papenbreer, G. Parente, A. Parra, M. Pech, F. Pedreira, J. Pe，kala,R. Pelayo, J. Pena-Rodriguez, L. A. S. Pereira,M. Perlin, L. Perrone, C. Peters, S. Petrera, J. Phuntsok, T. Pierog,M. Pimenta,V. Pirronello,M. Platino, J. Poh, B. Pont, C. Porowski, R. R. Prado, P. Privitera,M. Prouza, A. Puyleart, S. Querchfeld,S. Quinn, R. Ramos-Pollan, J. Rautenberg, D. Ravignani, M. Reininghaus, J. Ridky, F. Riehn,M. Risse, P. Ristori, V. Rizi, W. Rodrigues de Carvalho, J. Rodriguez Rojo,M. J. Roncoroni, M. Roth, E. Roulet, A. C. Rovero, P. Ruehl, S. J. Saffi, A. Saftoiu, F. Salamida,H. Salazar, G. Salina,J. D. Sanabria Gomez, F. Sanchez, E.M. Santos, E. Santos, F. Sarazin, R. Sarmento, C. Sarmiento-Cano, R. Sato,P. Savina,M. Schauer, V. Scherini, H. Schieler, M. Schimassek,M. Schimp, F. Schluter, D. Schmidt, O. Scholten, P. Schovanek, F. G. Schroder, S. Schroder, J. Schumacher, S. J. Sciutto,M. Scornavacche, R. C. Shellard, G. Sigl, G. Silli, O. Sima, R. Šmida,G.R. Snow, P. Sommers, J. F. Soriano, J. Souchard, R. Squartini, D. Stanca, S. Staniˇc, J. Stasielak, P. Stassi, M. Stolpovskiy,A. Streich, F. Suarez,M. Suarez-Duran, T. Sudholz, T. Suomijarvi, A.D. Supanitsky, J. Šupik, Z. Szadkowski, A. Taboada, O. A. Taborda, A. Tapia, C. Timmermans, C. J. Todero Peixoto, B. Tome, G. Torralba Elipe, A. Travaini, P. Travnicek,M. Trini, M. Tueros, R. Ulrich,M. Unger,M. Urban, J. F. Valdes Galicia, I. Valino, L. Valore, P. van Bodegom, A.M. van den Berg, A. van Vliet, E. Varela, B. Vargas Cardenas,D. Veberiˇc, C. Ventura, I. D. Vergara Quispe, V. Verzi, J. Vicha, L. Villasenor, J. Vink, S. Vorobiov, H. Wahlberg, A. A. Watson, M. Weber, A. Weindl,M.Wieden´ ski, L. Wiencke, H. Wilczyn´ ski, T.Winchen, M. Wirtz, D. Wittkowski, B. Wundheiler, L. Yang, A. Yushkov, E. Zas, D. Zavrtanik, M. Zavrtanik, L. Zehrer, A. Zepeda, B. Zimmermann,M. Ziolkowski, Z. Zongand F. Zuccarello
Data set attached as supplementary file
FRAM telescopes and their measurements of aerosol content at the Pierre Auger Observatory and at future sites of the Cherenkov Telescope Array
No full textA FRAM (F/(Ph)otometric Robotic Atmospheric Monitor) telescope is a system of a robotic mount, a large-format CCD camera and a fast telephoto lens that can be used for atmospheric monitoring at any site when information about the atmospheric transparency is required with high spatial or temporal resolution and where continuous use of laser-based methods for this purpose would interfere with other observations. The original FRAM has been operated at the Pierre Auger Observatory in Argentina for more than a decade, while three more FRAMs are foreseen to be used by the Cherenkov Telescope Array (CTA). The CTA FRAMs are being deployed ahead of time to characterize the properties of the sites prior to the operation of the CTA telescopes; one FRAM has been running on the planned future CTA site in Chile for a year while two others are expected to become operational before the end of 2018. We report on the hardware and current status of operation and/or deployment of all the FRAM instruments in question as well as on some of the preliminary results of integral aerosol measurements by the FRAMs in Argentina and Chile
Combined Search for UHE Neutrinos from Binary Black Hole Mergers with the Pierre Auger Observatory
No full textWe present searches for ultra-high energy (UHE) neutrinos (> 0.1 EeV) with the Pierre Auger Observatory, following up binary black hole (BBH) mergers detected by the LIGO and Virgo detectors via gravitational waves (GWs). In this work, the so-far published BBH mergers are combined as standard candles with a hypothetical isotropic UHE neutrino luminosity L(t − t0) as a function of the time after the respective merger, t − t0. The UHE neutrino emission spectrum is assumed to follow a power law distribution ∝ Ev−2. Using these assumptions, L(t − t0) is probed, taking into account the instantaneous effective area of the Pierre Auger Observatory to UHE neutrinos and the 3D sky localizations of the sources. No UHE neutrino candidates have been found and upper limits on L(t − t0) are obtained for the hypothetical cases of emissions lasting 24 hours and 60 days after the merger, respectively. The corresponding upper limit on the total energy per source emitted in UHE neutrinos does not depend on the emission duration and demonstrates the competitiveness of the Pierre Auger Observatory with dedicated neutrino telescopes
Impact of the magnetic horizon on the interpretation of the Pierre Auger Observatory spectrum and composition data
No full textThe flux of ultra-high energy cosmic rays reaching Earth above the ankle energy (5 EeV) can be described as a mixture of nuclei injected by extragalactic sources with very hard spectra and a low rigidity cutoff. Extragalactic magnetic fields existing between the Earth and the closest sources can affect the observed CR spectrum by reducing the flux of low-rigidity particles reaching Earth. We perform a combined fit of the spectrum and distributions of depth of shower maximum measured with the Pierre Auger Observatory including the effect of this magnetic horizon in the propagation of UHECRs in the intergalactic space. We find that, within a specific range of the various experimental and phenomenological systematics, the magnetic horizon effect can be relevant for turbulent magnetic field strengths in the local neighbourhood in which the closest sources lie of order B-rms similar or equal to (50-100) nG(20Mpc/ds)(100 kpc/L-coh)(1/2), with d(s) the typical intersource separation and L-coh the magnetic field coherence length. When this is the case, the inferred slope of the source spectrum becomes softer and can be closer to the expectations of diffusive shock acceleration, i.e., proportional to E-2. An additional cosmic-ray population with higher source density and softer spectra, presumably also extragalactic and dominating the cosmic-ray flux at EeV energies, is also required to reproduce the overall spectrum and composition results for all energies down to 0.6 EeV
Evidence for a mixed mass composition at the ‘ankle’ in the cosmic-ray spectrum
No full textWe report a first measurement for ultrahigh energy cosmic rays of the correlation between the depth of shower maximum and the signal in the water Cherenkov stations of air-showers registered simultaneously by the fluorescence and the surface detectors of the Pierre Auger Observatory. Such a correlation measurement is a unique feature of a hybrid air-shower observatory with sensitivity to both the electromagnetic and muonic components. It allows an accurate determination of the spread of primary masses in the cosmic-ray flux. Up till now, constraints on the spread of primary masses have been dominated by systematic uncertainties. The present correlation measurement is not affected by systematics in the measurement of the depth of shower maximum or the signal in the water Cherenkov stations. The analysis relies on general characteristics of air showers and is thus robust also with respect to uncertainties in hadronic event generators. The observed correlation in the energy range around the ‘ankle’ at lg(E/eV)=18.5–19.0lg(E/eV)=18.5–19.0 differs significantly from expectations for pure primary cosmic-ray compositions. A light composition made up of proton and helium only is equally inconsistent with observations. The data are explained well by a mixed composition including nuclei with mass A>4A>4. Scenarios such as the proton dip model, with almost pure compositions, are thus disfavored as the sole explanation of the ultrahigh-energy cosmic-ray flux at Earth
The FRAM robotic telescope for atmospheric monitoring at the Pierre Auger Observatory
No full textFRAM (F/Photometric Robotic Atmospheric Monitor) is a robotic telescope operated at the Pierre Auger Observatory in Argentina for the purposes of atmospheric monitoring using stellar photometry. As a passive system which does not produce any light that could interfere with the observations of the fluorescence telescopes of the observatory, it complements the active monitoring systems that use lasers. We discuss the applications of stellar photometry for atmospheric monitoring at optical observatories in general and the particular modes of operation employed by the Auger FRAM. We describe in detail the technical aspects of FRAM, the hardware and software requirements for a successful operation of a robotic telescope for such a purpose and their implementation within the FRAM system
The Auger Raman Lidar: several years of continuous observations
No full textThe Raman lidar at the Central (Raman) Laser Facility of the Pierre Auger Observatory in Argentina, has been operational since September 2013. In this paper, the Auger Raman Lidar performance is discussed in terms of the data quality for the assessment of the aerosol contribution to the atmospheric UV optical transparency, and how much this is important for the reconstruction of the UHECR properties, based on the Auger Fluorescence Detector observations
Atmospheric Monitoring at a Cosmic Ray Observatory - a long-lasting endeavour
No full textThe Pierre Auger Observatory for detecting ultrahigh energy cosmic rays has been founded in 1999. After a main planning and construction phase of about five years, the regular data taking started in 2004, but it took another four years until the full surface detector array was deployed. In parallel to the main detectors of the Observatory, a comprehensive set of instruments for monitoring the atmospheric conditions above the array was developed and installed as varying atmospheric conditions influence the development and detection of extensive air showers.The multitude of atmospheric monitoring installations at the Pierre Auger Observatory will be presented as well as the challenges and efforts to run such instruments for several decades
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