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

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

Auger South and North sky coverage Matter distribution at 7-21 Mpc Exclusion zones: north array south array Cronin, astro-ph/0402487

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

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 (10 000 km2 instead of 3000 km2) New collaborators are welcome