The Pierre Auger Observatory for the UHECR

Federico Sanchez, Dip.Fisica e INFN sezione Milano

● 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

A cosmic ray is not a ray...

What: subatomic

primaries

(e, p, He, C, N, O , Fe) and

secondaries

particles (Li, Be, B) from our galaxy. How and where: Produced by diffusive shock acceleration in SNR (super novae remnants)

Direct observation regime EAS regime

? ? ?

B source

n CR n Relic

B intergalactic

g

B galactic

Nucleons g Nucleons

How far?

X particle B halo

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,