Large scale anisotropy studies with the Pierre Auger Observatory

M. Grigat<sup>1</sup> for the Pierre Auger Collaboration<sup>2</sup>,

doi:doi:10.5194/astra-7-125-2011

Astrophys. Space Sci. Trans., 7, 125-129, 2011
www.astrophys-space-sci-trans.net/7/125/2011/
doi:10.5194/astra-7-125-2011
© Author(s) 2011. This work is distributed
under the Creative Commons Attribution 3.0 License.

Volume 7, issue 2

18 Apr 2011

Large scale anisotropy studies with the Pierre Auger Observatory
M. Grigat¹ for the Pierre Auger Collaboration²
¹RWTH Aachen University, Phys. Inst. IIIA, Aachen, Germany
²Observatorio Pierre Auger, Av. San Martín Norte 304, (5613) Malargüe, Mendoza, Argentina
^*Full author list: http://www.auger.org/archive/authors_2010_10.html

Received: 26 Oct 2010 – Revised: 05 Jan 2011 – Accepted: 05 Jan 2011 – Published: 18 Apr 2011

Abstract. The Pierre Auger Observatory in Argentina measures air showers initiated by cosmic rays at EeV energy scales (1 EeV = 10¹⁸ eV). An important goal of the collaboration is to study the distribution of arrival directions of the primary particles and quantify potential anisotropies therein. Using data collected by the surface detector (SD) array of the Pierre Auger Observatory since 1 January 2004, we study large scale anisotropies in different energy windows.

Modulations of the event rate within the period of a sidereal day are studied by means of a periodicity analysis accounting for local effects which may induce an artificial anisotropy. We present results for the event rate modulation in right ascension and derive upper limits for the equatorial component of a dipole amplitude (Auger Coll., 2011; Bonino, 2009).

Citation: M. Grigat¹ for the Pierre Auger Collaboration²: Large scale anisotropy studies with the Pierre Auger Observatory, Astrophys. Space Sci. Trans., 7, 125-129, doi:10.5194/astra-7-125-2011, 2011.

Astrophysics and Space Sciences Transactions

An Open Access Journal of the Arbeitsgemeinschaft Extraterrestrische Forschung e.V.