1. Auger North
Continuation of plans to construct the Pierre Auger Observatory:
detector systems located at two sites, on both hemispheres
Southern observatory (in Mendoza, Argentina) is under construction
Northern observatory (in Colorado, USA) is in planning stage
Henryk Wilczyński Network session at ApPEC SC meeting, Warsaw 3 July 2006

2. Motivation full sky coverage is essential
For explanation of the origin of UHE cosmic rays:
need to determine
distribution of arrival directions,
energy spectrum,
composition
Northern and Southern sky differ very much in distribution of matter seen:
local Supercluster in the North
Galactic center in the South
- different distributions of potential cosmic ray sources
- arrival direction anisotropy expected!
- identification of point sources, photons in UHECR much better with 2 sites
full sky coverage is essential

4. Auger South and North sky coverage
Matter distribution at 7-21 Mpc
Exclusion zones: north array south array
Cronin, astro-ph/

5. UHE photon identification
Different geomagnetic field conditions at Auger North and South sites
- very favorable for identification of photons from point sources

6. Northern Auger Observatory
Site chosen in South-Eastern Colorado
Basic detector systems similar to that at Southern site for seamless data integration
Possible modifications of original design considered:
include radio detection of extensive air showers
cover larger area ( km2 instead of 3000 km2)
New collaborators are welcome