34 research outputs found
Effects of asymmetric nanostructures on the extinction difference properties of actin biomolecules and filaments
10.1038/srep19658Scientific Reports61965
Substituted metal carbonyls. 26.1 One-step synthesis, structures, NMR, and dynamic laser-light scattering of Re2(μ-OMe)2[μ-Ph2P(CH2) nPPh2](CO)6 (n = 1-4)
Organometallics1551369-1374ORGN
The crystal structure and superconductivity of the new superconducting phase TlSr2Ca0.5Er0.5Cu2O6.75
Drying and germination of cupuassu (Theobroma grandiflorum (willd. Ex Spreng.) K. Schum.) seeds
Conservação de sementes de tangerina 'Cleópatra': teor de água e temperatura do ambiente
Changes in soluble sugars in relation to desiccation tolerance and effects of dehydration on freezing characteristics of Acer platanoides and Acer pseudoplatanus seeds
An Ultrahigh-energy -ray Bubble Powered by a Super PeVatron
International audienceWe report the detection of a -ray bubble spanning at least 100 in ultra high energy (UHE) up to a few PeV in the direction of the star-forming region Cygnus X, implying the presence Super PeVatron(s) accelerating protons to at least 10 PeV. A log-parabola form with the photon index is found fitting the gamma-ray energy spectrum of the bubble well. UHE sources, `hot spots' correlated with very massive molecular clouds, and a quasi-spherical amorphous -ray emitter with a sharp central brightening are observed in the bubble. In the core of , spatially associating with a region containing massive OB association (Cygnus OB2) and a microquasar (Cygnus X-3), as well as previously reported multi-TeV sources, an enhanced concentration of UHE -rays are observed with 2 photons at energies above 1 PeV. The general feature of the bubble, the morphology and the energy spectrum, are reasonably reproduced by the assumption of a particle accelerator in the core, continuously injecting protons into the ambient medium
LHAASO-KM2A detector simulation using Geant4
International audienceKM2A is one of the main sub-arrays of LHAASO, working on gamma ray astronomy and cosmic ray physics at energies above 10 TeV. Detector simulation is the important foundation for estimating detector performance and data analysis. It is a big challenge to simulate the KM2A detector in the framework of Geant4 due to the need to track numerous photons from a large number of detector units (>6000) with large altitude difference (30 m) and huge coverage (1.3 km^2). In this paper, the design of the KM2A simulation code G4KM2A based on Geant4 is introduced. The process of G4KM2A is optimized mainly in memory consumption to avoid memory overffow. Some simpliffcations are used to signiffcantly speed up the execution of G4KM2A. The running time is reduced by at least 30 times compared to full detector simulation. The particle distributions and the core/angle resolution comparison between simulation and experimental data of the full KM2A array are also presented, which show good agreement