A Targeted Search for Point Sources of EeV Photons with the Pierre Auger Observatory

Simultaneous measurements of air showers with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for EeV photon point sources. Several Galactic and extragalactic candidate objects are grouped in classes to reduce the statistical penalty of many trials from that of a blind search and are analyzed for a significant excess above the background expectation. The presented search does not find any evidence for photon emission at candidate sources, and combined p-values for every class are reported. Particle and energy flux upper limits are given for selected candidate sources. These limits significantly constrain predictions of EeV proton emission models from non-transient Galactic and nearby extragalactic sources, as illustrated for the particular case of the Galactic center region

Características da carcaça de bovinos de quatro grupos genéticos submetidos a dietas com ou sem adição de gordura protegida Carcass characteristics of bovines from four genetic groups fed diets with or without protected fat

Com o objetivo de avaliar o rendimento e as características de carcaça de quatro grupos genéticos de bovinos, foram abatidos 32 animais machos inteiros, dos grupos Nelore (N), F1 Canchim x Nelore (CN), F1 Limousin x Nelore (LN) e F1 Aberdeen Angus x Nelore (AN), com idade aproximada de 19 meses e peso vivo médio de 558 kg, terminados em regime de confinamento, recebendo dietas com ou sem adição de gordura protegida, durante 166 dias. O delineamento experimental utilizado foi inteiramente casualizado, com quatro repetições, seguindo esquema fatorial 2 x 4 (dieta, grupo genético). Observou-se efeito do grupo genético sobre o rendimento de cortes primários, tendo o grupo AN apresentado as maiores médias de dianteiro (41,65%) e ponta de agulha (13.90%) e o grupo LN, o maior rendimento de traseiro (47,40%). A área de olho de lombo (AOL) sofreu efeito da dieta, apresentando médias de 81,31 cm² vs. 88,50cm², para as dietas sem e com gordura protegida, respectivamente. A composição física da carcaça foi influenciada pelo grupo genético, tendo o grupo LN apresentado a maior porcentagem de músculo (63,62%) e a menor porcentagem de tecido adiposo (21,65%), enquanto o grupo Nelore apresentou a maior porcentagem de tecido adiposo (28,28%) e menor porcentagem de músculo (56,76%). A composição química da seção HH sofreu efeito do grupo genético, tendo sido observados os maiores teores de proteína bruta nos grupos LN (27,24%) e CN (26,10%) e de extrato etéreo no grupo Nelore (68,35%), que não diferiu do grupo AN (68,02%). Os menores teores de Ca, P e Mg (2,62; 1,32; e 0,081%) foram observados no grupo Nelore.<br>The objective of this experiment was to evaluate the yield and carcass characteristics of steers from the following four genetic group: Nellore (N), F1 Canchim x Nellore (CN), F1 Limousin x Nellore (LN) and F1 Aberdeen Angus x Nellore (NA). For this purpose, 32 steers, with age of 19 months and live weight average of 558 kg, raised in confinement and fed diet with and without protected fat for 166 days, were slaughtered. A completely randomized design, with four replicates, following a factorial scheme of 2 x 4 (diet, genetic group), was used. The effect of genetic group was observed on the prime cuts yield and the group NA presented the greatest yield means of the hindquarter (41.65%) and spare ribs (13.90%) and the group LN presented a greater yield of forequarter (47.40%). The loin eye area (AOL) was affected by the diet, showing means of 81.31 cm² vs. 88.50 cm² in the diets without and with protected fat, respectively. The physical composition of the carcass was affected by the genetic group, and the group LN showed the greatest percentage of muscle (63.62%) and the lowest percentage of fat tissue (21.65%), while the group Nellore showed the greatest percentage of fat tissue (28.28%) and the lowest percentage of muscle (56.76%). The chemical composition of the HH section was affected by the genetic group, and the greatest contents of crude protein were observed in the groups LN (27.24%) and CN (26.10%), and the ether extract in the group Nellore (68.35%), that did not differ form the AN (68.02%). The lowest contents of Ca, P and Mg (2.62; 1.32 and 0.081%) were observed in the group Nellore

Search for magnetically-induced signatures in the arrival directions of ultra-high-energy cosmic rays measured at the Pierre Auger Observatory

We search for signals of magnetically-induced effects in the arrival directions of ultra-high-energy cosmic rays detected at the Pierre Auger Observatory. We apply two different methods. One is a search for sets of events that show a correlation between their arrival direction and the inverse of their energy, which would be expected if they come from the same point-like source, they have the same electric charge and their deflection is relatively small and coherent. We refer to these sets of events as "multiplets". The second method, called "thrust", is a principal axis analysis aimed to detect the elongated patterns in a region of interest. We study the sensitivity of both methods using a benchmark simulation and we apply them to data in two different searches. The first search is done assuming as source candidates a list of nearby active galactic nuclei and starburst galaxies. The second is an all-sky blind search. We report the results and we find no statistically significant features. We discuss the compatibility of these results with the indications on the mass composition inferred from data of the Pierre Auger Observatory. © 2020 IOP Publishing Ltd and Sissa Medialab

Observation of inclined EeV air showers with the radio detector of the Pierre Auger Observatory

With the Auger Engineering Radio Array (AERA) of the Pierre Auger Observatory, we have observed the radio emission from 561 extensive air showers with zenith angles between 60 and 84. In contrast to air showers with more vertical incidence, these inclined air showers illuminate large ground areas of several km2 with radio signals detectable in the 30 to 80 MHz band. A comparison of the measured radio-signal amplitudes with Monte Carlo simulations of a subset of 50 events for which we reconstruct the energy using the Auger surface detector shows agreement within the uncertainties of the current analysis. As expected for forward-beamed radio emission undergoing no significant absorption or scattering in the atmosphere, the area illuminated by radio signals grows with the zenith angle of the air shower. Inclined air showers with EeV energies are thus measurable with sparse radio-antenna arrays with grid sizes of a km or more. This is particularly attractive as radio detection provides direct access to the energy in the electromagnetic cascade of an air shower, which in case of inclined air showers is not accessible by arrays of particle detectors on the ground