Treasure Maps for Detections of Extreme Energy Cosmic Rays

Abstract

The origin of Ultra High Energy Cosmic Rays is a 60-year old mystery. We show that with more events at the highest energies (above 150~EeV) it may be possible to limit the character of the sources and learn about the intervening magnetic fields. Individual sources become more prominent, relative to the background, as the horizon diminishes. An event-by-event, composition-dependent observatory would allow a ``tomography'' of the sources as different mass and energy groups probe different GZK horizons. A major goal here is to provide a methodology to distinguish between steady and transient or highly variable sources. Using recent Galactic magnetic field models, we calculate ``treasure'' sky maps to identify the most promising directions for detecting Extreme Energy Cosmic Rays (EECR) doublets, events that are close in arrival time and direction. On this basis, we predict the incidence of doublets as a function of the nature of the source host galaxy. Based on the asymmetry in the distribution of time delays, we show that observation of doublets might distinguish source models. In particular the Telescope Array hotspot could exhibit temporal variability as it is in a ``magnetic window'' of small time delays. These considerations could improve the use of data with existing facilities and the planning of future ones such as Global Cosmic Ray Observatory - GCOS.

20 pages, 13 figures, submitted to the Astrophysical Journal

References in corpus (16)

• Updated Nearby Galaxy Catalog
• Observation of a Large-scale Anisotropy in the Arrival Directions of Cosmic Rays above $8\times 10^{18}$ eV
• Indications of Intermediate-Scale Anisotropy of Cosmic Rays with Energy Greater Than 57 EeV in the Northern Sky Measured with the Surface Detector of the Telescope Array Experiment
• Giant AGN Flares and Cosmic Ray Bursts
• A unified picture for low-luminosity and long gamma-ray bursts based on the extended progenitor of llgrb 060218/SN 2006aj
• The Muon Puzzle in cosmic-ray induced air showers and its connection to the Large Hadron Collider
• Measurement of the rate of stellar tidal disruption flares
• A new view on Auger data and cosmogenic neutrinos in light of different nuclear disintegration and air-shower models
• A bright gamma-ray flare interpreted as a giant magnetar flare in NGC 253
• Radio galaxies of the local universe: all-sky catalog, luminosity functions, and clustering
• Arrival Directions of Cosmic Rays above 32 EeV from Phase One of the Pierre Auger Observatory
• Propagation of high-energy cosmic rays in extragalactic turbulent magnetic fields: resulting energy spectrum and composition
• Constraints from Faraday rotation on the magnetic field structure in the Galactic halo
• The extragalactic ultra-high energy cosmic-ray dipole
• A global autocorrelation study after the first Auger data: impact on the number density of UHECR sources
• Towards unravelling the structural distribution of ultra-high-energy cosmic ray sources

Cited by in corpus (4)

• The large-scale anisotropy and flux (de-)magnification of ultra-high-energy cosmic rays in the Galactic magnetic field
• Revisiting Propagation Delays of Ultra-High-Energy Cosmic Rays from Long-lived Sources
• Beyond the Local Void: A data-driven search for the origins of the Amaterasu particle
• Neutrino anisotropy as a probe of extreme astrophysical accelerators