The effect of the geomagnetic field on cosmic ray energy estimates and large scale anisotropy searches on data from the Pierre Auger Observatory

ArXiv 1111.7122 (2011)

Authors:

P Abreu, M Aglietta, EJ Ahn, IFM Albuquerque, D Allard, I Allekotte, J Allen, P Allison, J Alvarez Castillo, J Alvarez-Muñiz, M Ambrosio, A Aminaei, L Anchordoqui, S Andringa, T Antičić, A Anzalone, C Aramo, E Arganda, F Arqueros, H Asorey, P Assis, J Aublin, M Ave, M Avenier, G Avila, T Bäcker, M Balzer, KB Barber, AF Barbosa, R Bardenet, SLC Barroso, B Baughman, J Bäuml, JJ Beatty, BR Becker, KH Becker, A Bellétoile, JA Bellido, S BenZvi, C Berat, X Bertou, PL Biermann, P Billoir, F Blanco, M Blanco, C Bleve, H Blümer, M Boháčová, D Boncioli, C Bonifazi, R Bonino, N Borodai, J Brack, P Brogueira, WC Brown, R Bruijn, P Buchholz, A Bueno, RE Burton, KS Caballero-Mora, L Caramete, R Caruso, A Castellina, O Catalano, G Cataldi, L Cazon, R Cester, J Chauvin, SH Cheng, A Chiavassa, JA Chinellato, A Chou, J Chudoba, RW Clay, MR Coluccia, R Conceição, F Contreras, H Cook, MJ Cooper, J Coppens, A Cordier, S Coutu, CE Covault, A Creusot, A Criss, J Cronin, A Curutiu, S Dagoret-Campagne, R Dallier, S Dasso, K Daumiller, BR Dawson, RM de Almeida, M De Domenico, C De Donato, SJ de Jong, G De La Vega, WJM de Mello Junior, JRT de Mello Neto, I De Mitri, V de Souza, KD de Vries, G Decerprit, L del Peral, M del Río, O Deligny, H Dembinski, N Dhital, C Di Giulio, JC Diaz, ML Díaz Castro, PN Diep, C Dobrigkeit, W Docters, JC D'Olivo, PN Dong, A Dorofeev, JC dos Anjos, MT Dova, D D'Urso, I Dutan, J Ebr, R Engel, M Erdmann, CO Escobar, J Espadanal, A Etchegoyen, P Facal San Luis, I Fajardo Tapia, H Falcke, G Farrar, AC Fauth, N Fazzini, AP Ferguson, A Ferrero, B Fick, A Filevich, A Filipčič, S Fliescher, CE Fracchiolla, ED Fraenkel, U Fröhlich, B Fuchs, R Gaior, RF Gamarra, S Gambetta, B García, D García Gámez, D Garcia-Pinto, A Gascon, H Gemmeke, K Gesterling, PL Ghia, U Giaccari, M Giller, H Glass, MS Gold, G Golup, F Gomez Albarracin, M Gómez Berisso, P Gonçalves, D Gonzalez, JG Gonzalez, B Gookin, D Góra, A Gorgi, P Gouffon, SR Gozzini, E Grashorn, S Grebe, N Griffith, M Grigat, AF Grillo, Y Guardincerri, F Guarino, GP Guedes, A Guzman, JD Hague, P Hansen, D Harari, S Harmsma, JL Harton, A Haungs, T Hebbeker, D Heck, AE Herve, C Hojvat, N Hollon, VC Holmes, P Homola, JR Hörandel, A Horneffer, M Hrabovský, T Huege, A Insolia, F Ionita, A Italiano, C Jarne, S Jiraskova, M Josebachuili, K Kadija, KH Kampert, P Karhan, P Kasper, B Kégl, B Keilhauer, A Keivani, JL Kelley, E Kemp, RM Kieckhafer, HO Klages, M Kleifges, J Kleinfeller, J Knapp, D-H Koang, K Kotera, N Krohm, O Krömer, D Kruppke-Hansen, F Kuehn, D Kuempel, JK Kulbartz, N Kunka, G La Rosa, C Lachaud, P Lautridou, MSAB Leão, D Lebrun, P Lebrun, MA Leigui de Oliveira, A Lemiere, A Letessier-Selvon, I Lhenry-Yvon, K Link, R López, A Lopez Agüera, K Louedec, J Lozano Bahilo, L Lu, A Lucero, M Ludwig, H Lyberis, MC Maccarone, C Macolino, S Maldera, D Mandat, P Mantsch, AG Mariazzi, J Marin, V Marin, IC Maris, HR Marquez Falcon, G Marsella, D Martello, L Martin, H Martinez, O Martínez Bravo, HJ Mathes, J Matthews, JAJ Matthews, G Matthiae, D Maurizio, PO Mazur, G Medina-Tanco, M Melissas, D Melo, E Menichetti, A Menshikov, P Mertsch, C Meurer, S Mićanović, MI Micheletti, W Miller, L Miramonti, L Molina-Bueno, S Mollerach, M Monasor, D Monnier Ragaigne, F Montanet, B Morales, C Morello, E Moreno, JC Moreno, C Morris, M Mostafá, CA Moura, S Mueller, MA Muller, G Müller, M Münchmeyer, R Mussa, G Navarra, JL Navarro, S Navas, P Necesal, L Nellen, A Nelles, J Neuser, PT Nhung, L Niemietz, N Nierstenhoefer, D Nitz, D Nosek, L Nožka, M Nyklicek, J Oehlschläger, A Olinto, P Oliva, VM Olmos-Gilbaja, M Ortiz, N Pacheco, D Pakk Selmi-Dei, M Palatka, J Pallotta, N Palmieri, G Parente, E Parizot, A Parra, RD Parsons, S Pastor, T Paul, M Pech, J Pȩkala, R Pelayo, IM Pepe, L Perrone, R Pesce, E Petermann, S Petrera, P Petrinca, A Petrolini, Y Petrov, J Petrovic, C Pfendner, N Phan, R Piegaia, T Pierog, P Pieroni, M Pimenta, V Pirronello, M Platino, VH Ponce, M Pontz, P Privitera, M Prouza, EJ Quel, S Querchfeld, J Rautenberg, O Ravel, D Ravignani, B Revenu, J Ridky, S Riggi, M Risse, P Ristori, H Rivera, V Rizi, J Roberts, C Robledo, W Rodrigues de Carvalho, G Rodriguez, J Rodriguez Martino, J Rodriguez Rojo, I Rodriguez-Cabo, MD Rodríguez-Frías, G Ros, J Rosado, T Rossler, M Roth, B Rouillé-d'Orfeuil, E Roulet, AC Rovero, C Rühle, F Salamida, H Salazar, G Salina, F Sánchez, CE Santo, E Santos, EM Santos, F Sarazin, B Sarkar, S Sarkar, R Sato, N Scharf, V Scherini, H Schieler, P Schiffer, A Schmidt, F Schmidt, O Scholten, H Schoorlemmer, J Schovancova, P Schovánek, F Schröder, S Schulte, D Schuster, SJ Sciutto, M Scuderi, A Segreto, M Settimo, A Shadkam, RC Shellard, I Sidelnik, G Sigl, HH Silva Lopez, A Śmiałkowski, R Šmída, GR Snow, P Sommers, J Sorokin, H Spinka, R Squartini, S Stanic, J Stapleton, J Stasielak, M Stephan, E Strazzeri, A Stutz, F Suarez, T Suomijärvi, AD Supanitsky, T Šuša, MS Sutherland, J Swain, Z Szadkowski, M Szuba, A Tamashiro, A Tapia, M Tartare, O Taşcău, CG Tavera Ruiz, R Tcaciuc, D Tegolo, NT Thao, D Thomas, J Tiffenberg, C Timmermans, DK Tiwari, W Tkaczyk, CJ Todero Peixoto, B Tomé, A Tonachini, P Travnicek, DB Tridapalli, G Tristram, E Trovato, M Tueros, R Ulrich, M Unger, M Urban, JF Valdés Galicia, I Valiño, L Valore, AM van den Berg, E Varela, B Vargas Cárdenas, JR Vázquez, RA Vázquez, D Veberič, V Verzi, J Vicha, M Videla, L Villaseñor, H Wahlberg, P Wahrlich, O Wainberg, D Walz, D Warner, AA Watson, M Weber, K Weidenhaupt, A Weindl, S Westerhoff, BJ Whelan, G Wieczorek, L Wiencke, B Wilczyńska, H Wilczyński, M Will, C Williams, T Winchen, MG Winnick, M Wommer, B Wundheiler, T Yamamoto, T Yapici, P Younk, G Yuan, A Yushkov, B Zamorano, E Zas, D Zavrtanik, M Zavrtanik, I Zaw, A Zepeda, M Zimbres Silva, M Ziolkowski

Abstract:

We present a comprehensive study of the influence of the geomagnetic field on the energy estimation of extensive air showers with a zenith angle smaller than $60^\circ$, detected at the Pierre Auger Observatory. The geomagnetic field induces an azimuthal modulation of the estimated energy of cosmic rays up to the ~2% level at large zenith angles. We present a method to account for this modulation of the reconstructed energy. We analyse the effect of the modulation on large scale anisotropy searches in the arrival direction distributions of cosmic rays. At a given energy, the geomagnetic effect is shown to induce a pseudo-dipolar pattern at the percent level in the declination distribution that needs to be accounted for.

Trigger and Aperture of the Surface Detector Array of the Pierre Auger Observatory

ArXiv 1111.6764 (2011)

Authors:

J Abraham, P Abreu, M Aglietta, C Aguirre, EJ Ahn, D Allard, I Allekotte, J Allen, J Alvarez-Muñiz, M Ambrosio, L Anchordoqui, S Andringa, A Anzalone, C Aramo, E Arganda, S Argirò, K Arisaka, F Arneodo, F Arqueros, T Asch, H Asorey, P Assis, J Aublin, M Ave, G Avila, T Bäcker, D Badagnani, KB Barber, AF Barbosa, SLC Barroso, B Baughman, P Bauleo, JJ Beatty, T Beau, BR Becker, KH Becker, A Bellétoile, JA Bellido, S BenZvi, C Berat, P Bernardini, X Bertou, PL Biermann, P Billoir, O Blanch-Bigas, F Blanco, C Bleve, H Blümer, M Boháčová, D Boncioli, C Bonifazi, R Bonino, N Borodai, J Brack, P Brogueira, WC Brown, R Bruijn, P Buchholz, A Bueno, RE Burton, NG Busca, KS Caballero-Mora, L Caramete, R Caruso, W Carvalho, A Castellina, O Catalano, L Cazon, R Cester, J Chauvin, A Chiavassa, JA Chinellato, A Chou, J Chudoba, J Chye, RW Clay, E Colombo, R Conceição, B Connolly, F Contreras, J Coppens, A Cordier, U Cotti, S Coutu, CE Covault, A Creusot, A Criss, J Cronin, A Curutiu, S Dagoret-Campagne, R Dallier, K Daumiller, BR Dawson, RM de Almeida, M De Domenico, C De Donato, SJ de Jong, G De La Vega, WJM de Mello Junior, JRT de Mello Neto, I De Mitri, V de Souza, KD de Vries, G Decerprit, L del Peral, O Deligny, A Della Selva, C Delle Fratte, H Dembinski, C Di Giulio, JC Diaz, PN Diep, C Dobrigkeit, JC D'Olivo, PN Dong, A Dorofeev, JC dos Anjos, MT Dova, D D'Urso, I Dutan, MA DuVernois, R Engel, M Erdmann, CO Escobar, A Etchegoyen, P Facal San Luis, H Falcke, G Farrar, AC Fauth, N Fazzini, F Ferrer, A Ferrero, B Fick, A Filevich, A Filipčič, I Fleck, S Fliescher, CE Fracchiolla, ED Fraenkel, W Fulgione, RF Gamarra, S Gambetta, B García, D García Gámez, D Garcia-Pinto, X Garrido, G Gelmini, H Gemmeke, PL Ghia, U Giaccari, M Giller, H Glass, LM Goggin, MS Gold, G Golup, F Gomez Albarracin, M Gómez Berisso, P Gonçalves, M Gonçalves do Amaral, D Gonzalez, JG Gonzalez, D Góra, A Gorgi, P Gouffon, SR Gozzini, E Grashorn, S Grebe, M Grigat, AF Grillo, Y Guardincerri, F Guarino, GP Guedes, J Gutiérrez, JD Hague, V Halenka, P Hansen, D Harari, S Harmsma, JL Harton, A Haungs, MD Healy, T Hebbeker, G Hebrero, D Heck, C Hojvat, VC Holmes, P Homola, JR Hörandel, A Horneffer, M Hrabovský, T Huege, M Hussain, M Iarlori, A Insolia, F Ionita, A Italiano, S Jiraskova, M Kaducak, KH Kampert, T Karova, P Kasper, B Kégl, B Keilhauer, E Kemp, RM Kieckhafer, HO Klages, M Kleifges, J Kleinfeller, R Knapik, J Knapp, D-H Koang, A Krieger, O Krömer, D Kruppke-Hansen, F Kuehn, D Kuempel, K Kulbartz, N Kunka, A Kusenko, G La Rosa, C Lachaud, BL Lago, P Lautridou, MSAB Leão, D Lebrun, P Lebrun, J Lee, MA Leigui de Oliveira, A Lemiere, A Letessier-Selvon, M Leuthold, I Lhenry-Yvon, R López, A Lopez Agüera, K Louedec, J Lozano Bahilo, A Lucero, H Lyberis, MC Maccarone, C Macolino, S Maldera, D Mandat, P Mantsch, AG Mariazzi, IC Maris, HR Marquez Falcon, D Martello, O Martínez Bravo, HJ Mathes, J Matthews, JAJ Matthews, G Matthiae, D Maurizio, PO Mazur, M McEwen, RR McNeil, G Medina-Tanco, M Melissas, D Melo, E Menichetti, A Menshikov, R Meyhandan, MI Micheletti, G Miele, W Miller, L Miramonti, S Mollerach, M Monasor, D Monnier Ragaigne, F Montanet, B Morales, C Morello, JC Moreno, C Morris, M Mostafá, CA Moura, S Mueller, MA Muller, R Mussa, G Navarra, JL Navarro, S Navas, P Necesal, L Nellen, C Newman-Holmes, D Newton, PT Nhung, N Nierstenhoefer, D Nitz, D Nosek, L Nožka, M Nyklicek, J Oehlschläger, A Olinto, P Oliva, VM Olmos-Gilbaja, M Ortiz, N Pacheco, D Pakk Selmi-Dei, M Palatka, J Pallotta, G Parente, E Parizot, S Parlati, S Pastor, M Patel, T Paul, V Pavlidou, K Payet, M Pech, J Pȩkala, IM Pepe, L Perrone, R Pesce, E Petermann, S Petrera, P Petrinca, A Petrolini, Y Petrov, J Petrovic, C Pfendner, R Piegaia, T Pierog, M Pimenta, T Pinto, V Pirronello, O Pisanti, M Platino, J Pochon, VH Ponce, M Pontz, P Privitera, M Prouza, EJ Quel, J Rautenberg, O Ravel, D Ravignani, A Redondo, B Revenu, FAS Rezende, J Ridky, S Riggi, M Risse, C Rivière, V Rizi, C Robledo, G Rodriguez, J Rodriguez Martino, J Rodriguez Rojo, I Rodriguez-Cabo, MD Rodríguez-Frías, G Ros, J Rosado, T Rossler, M Roth, B Rouillé-d'Orfeuil, E Roulet, AC Rovero, F Salamida, H Salazar, G Salina, F Sánchez, M Santander, CE Santo, EM Santos, F Sarazin, S Sarkar, R Sato, N Scharf, V Scherini, H Schieler, P Schiffer, A Schmidt, F Schmidt, T Schmidt, O Scholten, H Schoorlemmer, J Schovancova, P Schovánek, F Schroeder, S Schulte, F Schüssler, D Schuster, SJ Sciutto, M Scuderi, A Segreto, D Semikoz, M Settimo, RC Shellard, I Sidelnik, BB Siffert, G Sigl, A Śmiałkowski, R Šmída, BE Smith, GR Snow, P Sommers, J Sorokin, H Spinka, R Squartini, E Strazzeri, A Stutz, F Suarez, T Suomijärvi, AD Supanitsky, MS Sutherland, J Swain, Z Szadkowski, A Tamashiro, A Tamburro, T Tarutina, O Taşcău, R Tcaciuc, D Tcherniakhovski, D Tegolo, NT Thao, D Thomas, R Ticona, J Tiffenberg, C Timmermans, W Tkaczyk, CJ Todero Peixoto, B Tomé, A Tonachini, I Torres, P Travnicek, DB Tridapalli, G Tristram, E Trovato, M Tueros, R Ulrich, M Unger, M Urban, JF Valdés Galicia, I Valiño, L Valore, AM van den Berg, JR Vázquez, RA Vázquez, D Veberič, A Velarde, T Venters, V Verzi, M Videla, L Villaseñor, S Vorobiov, L Voyvodic, H Wahlberg, P Wahrlich, O Wainberg, D Warner, AA Watson, S Westerhoff, BJ Whelan, G Wieczorek, L Wiencke, B Wilczyńska, H Wilczyński, C Wileman, MG Winnick, H Wu, B Wundheiler, T Yamamoto, P Younk, G Yuan, A Yushkov, E Zas, D Zavrtanik, M Zavrtanik, I Zaw, A Zepeda, M Ziolkowski

Abstract:

The surface detector array of the Pierre Auger Observatory consists of 1600 water-Cherenkov detectors, for the study of extensive air showers (EAS) generated by ultra-high-energy cosmic rays. We describe the trigger hierarchy, from the identification of candidate showers at the level of a single detector, amongst a large background (mainly random single cosmic ray muons), up to the selection of real events and the rejection of random coincidences. Such trigger makes the surface detector array fully efficient for the detection of EAS with energy above $3\times 10^{18}$ eV, for all zenith angles between 0$^\circ$ and 60$^\circ$, independently of the position of the impact point and of the mass of the primary particle. In these range of energies and angles, the exposure of the surface array can be determined purely on the basis of the geometrical acceptance.

Gravitino cosmology with a very light neutralino

ArXiv 1111.5715 (2011)

Authors:

Herbi K Dreiner, Marja Hanussek, Jong-Soo Kim, Subir Sarkar

Abstract:

It has been shown that very light or even massless neutralinos are consistent with all current experiments, given non-universal gaugino masses. Furthermore, a very light neutralino is consistent with astrophysical bounds from supernov{\ae} and cosmological bounds on dark matter. Here we study the cosmological constraints on this scenario from Big Bang nucleosynthesis taking gravitinos into account and find that a very light neutralino is even favoured by current observations.

Gravitino cosmology with a very light neutralino

(2011)

Authors:

Herbi K Dreiner, Marja Hanussek, Jong-Soo Kim, Subir Sarkar

IceCube - Astrophysics and Astroparticle Physics at the South Pole

ArXiv 1111.5188 (2011)

Abstract:

The IceCube Neutrino Observatory at the South Pole has been completed in December 2010. In this paper we describe the final detector and report results on physics and performance using data taken at different stages of the yet incomplete detector. No signals for cosmic neutrinos from point sources and diffuse fluxes have been found. Prospects of these searches, including the setup of multi-messenger programs, are discussed. The limits on neutrinos from GRBs, being far below model predictions, require a reevaluation of GRB model assumptions. Various measurements of cosmic ray properties have been obtained from atmospheric muon and neutrino spectra and from air shower measurements; these results will have an important impact on model developments. IceCube observed an anisotropy of cosmic rays on multiple angular scales, for the first time in the Southern sky. The unique capabilities of IceCube for monitoring transient low energy events are briefly discussed. Finally an outlook to planned extensions is given which will improve the sensitivities both on the low and high energy side.