● What a cosmic ray (CR) and a ultra high energy cosmic ray (UHECR) are?

● What do we know and what we would like to know about them?

● How do we detect them?

● First Auger public results and conclusions

The Pierre Auger Observatory for the UHECR

Federico Sanchez, Dip.Fisica e INFN sezione Milano

A cosmic ray is not a ray...

subatomic primaries (e, p, He, C, N, O , Fe)and secondaries particles (Li, Be, B)from our galaxy.

EAS regimeDirectobservationregime

? ? ?

Produced by diffusive shock acceleration in SNR (super novae remnants)

What:

How and where:

X particle

How far?

B intergalactic

B galactic

B halo

B source

CR

Relic

Nucleons

Nucleons

Gaucho

SD

FD

HYB

Spectrum

Conclusions:

● The Pierre Auger Observatory started regular data taking in January 2004 and released its firsts physics results in August 2005.

● The southern site construction will finish by the end of 2006.

● The northern site is in R&D phase.

Thank you,