New electronics for the surface detectors of the Pierre Auger Observatory

International audienceThe surface detector array of the Pierre Auger Observatory consists of 1660 water Cherenkov detectors that sample the charged particles and photons of energetic cosmic ray air showers at the ground. In the framework of the planned upgrade of the Auger Observatory, AugerPrime, new electronics has been designed for the surface detectors. The electronics upgrade includes higher sampling frequency, increased dynamic range, increased processing capability, improved timing with up-to-date GPS receivers, and a better calibration and monitoring system. It will also process the data of the additional scintillator detectors planned for the upgrade

A measurement of the average longitudinal development profile of cosmic ray air showers between 10(17) and 10(18) eV

Copyright © 2001 Elsevier Science B.V. All rights reserved.The average extensive air shower longitudinal development profile is measured. Events between 1017 and 1018 eV recorded by the HiRes/MIA hybrid experiment are used for the average profile. Several functional forms are examined using this average profile. The best-fit parameters for the above functions are determined. © 2001 Elsevier Science B.V.http://www.elsevier.com/wps/find/journaldescription.cws_home/523319/description#descriptio

Snowmass Cosmic Frontiers 6 (CF6) Working Group Summary --The Bright Side of the Cosmic Frontier: Cosmic Probes of Fundamental Physics

Report of the CF6 Working Group at Snowmass 2013. Topics addressed include ultra-high energy cosmic rays, neutrinos, gamma rays, baryogenesis, and experiments probing the fundamental nature of spacetime.Report of the CF6 Working Group at Snowmass 2013. Topics addressed include ultra-high energy cosmic rays, neutrinos, gamma rays, baryogenesis, and experiments probing the fundamental nature of spacetime

Multi-messenger Observations of a Binary Neutron Star Merger

International audienceOn 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of $\sim 1.7\,{\rm{s}}$ with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg(2) at a luminosity distance of ${40}_{-8}^{+8}$ Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 $\,{M}_{\odot }$. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at $\sim 40\,{\rm{Mpc}}$) less than 11 hours after the merger by the One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ∼10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position $\sim 9$ and $\sim 16$ days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta