ICRC2015

Session

Parallel CR07 EAS mass

31 Jul 2015, 14:00

World Forum

618. Report of the Working Group on the Composition of Ultra-High Energy Cosmic Rays

Michael Unger (NYU & KIT)

31/07/2015, 14:00

CR-EX

Oral contribution

The atmospheric depth $X_\mathrm{max}$ at which the particle number of an air shower reaches its maximum is a good indicator for the mass of the primary particle. We present a comparison of the energy evolution of the mean of $X_\mathrm{max}$ as measured by the Telescope Array and Pierre Auger Collaborations. After accounting for the different resolutions, acceptances and analysis...

796. Composition at the ``ankle'' measured by the Pierre Auger Observatory: pure or mixed?

Dr Alexey Yushkov (University of Siegen)

31/07/2015, 14:15

CR-EX

Oral contribution

We report for the first time on the measurement of the correlation between the depth of shower maximum and the signal in water-Cherenkov stations for events reconstructed by both the fluorescence and surface detectors of the Pierre Auger Observatory. Such a correlated measurement is a unique feature of a hybrid air shower observatory and allows us to determine the purity of the cosmic-ray...

863. Summary of UHECR composition measurements by the Telescope Array Experiment

John Belz (University of Utah)

31/07/2015, 14:30

CR-EX

Oral contribution

We study the chemical composition of ultrahigh energy cosmic rays primarily using the Xmax technique. The reconstruction techniques use events either seen by two of the TA fluorescence detectors (stereo mode), or by one fluorescence detector, and one fluorescence detector and the TA surface detector (hybrid mode). Each technique has its own acceptance imprinted on the data. We compare the...

1176. Measurements of the first two moments of the depth of shower maximum over nearly three decades of energy, combining data from the standard Pierre Auger fluorescence detector and the High Elevation Fluorescence Telescopes

Dr Alessio Porcelli (Universite de Geneve (CH))

31/07/2015, 14:45

CR-EX

Oral contribution

For the first time the Pierre Auger Collaboration presents $\langle X_\mathrm{max}\rangle$ and $\sigma(X_\mathrm{max})$ measurements covering nearly three decades of energy. In this analysis we include new $X_\mathrm{max}$ data obtained with the Pierre Auger High Elevation Fluorescence Telescopes (HEAT) enhancement. The HEAT telescopes cover a field of view ranging from $30^\circ$ to...

781. Telescope Array search for photons and neutrinos with the surface detector data

Grigory Rubtsov (INR RAS)

31/07/2015, 15:00

CR-EX

Oral contribution

We report on a search for ultra-high-energy photons with a multivariate analysis technique based on the properties of shower fronts of events observed by the Telescope Array surface detector. We present the point source photon flux upper limits for all directions in the Northern hemisphere. The revised constraints on the diffuse flux of the primary photons with energies greater than 10^19 eV...

920. Measuring the cosmic ray mass composition with LOFAR

Stijn Buitink (Vrije Universiteit Brussel (VUB))

31/07/2015, 15:15

CR-EX

Oral contribution

The LOFAR radio telescope measures the radio emission from air showers with unprecedented precision. In the dense core individual air showers are detected by hundreds of dipole antennas. The complicated radio pattern on the ground is accurately reproduced by modern radio simulation codes and contains information about the longitudinal shower development. With a hybrid reconstruction technique,...