Large scale distribution of ultra high energy cosmic rays detected at the Pierre Auger Observatory with zenith angles up to 80$^\circ$
A. Aab
,
M. Avenier
(1)
,
C. Berat
(1)
,
S. Le Coz
(1)
,
D. Lebrun
(1)
,
K. Louedec
(1)
,
F. Montanet
(1)
,
A. Stutz
(1)
,
Richard Dallier
(2, 3)
,
F. Gate
(3)
,
Pascal Lautridou
(3)
,
J. Maller
(3)
,
V. Marin
(3)
,
Lilian Martin
(3, 2)
,
O. Ravel
(3)
,
Benoît Revenu
(3)
,
Imen Al Samarai
(4)
,
O. Deligny
(4)
,
I. Lhenry-Yvon
(4)
,
D. Martraire
(4)
,
F. Salamida
(4)
,
T. Suomijärvi
(4)
,
A. Cordier
(5)
,
D. Garcia-Gamez
(5)
,
Balázs Kégl
(5)
,
D. Monnier Ragaigne
(5)
,
D. Veberic
(5)
A. Aab
- Fonction : Auteur
C. Berat
- Fonction : Auteur
- PersonId : 739578
- IdHAL : corinne-berat
- ORCID : 0000-0001-8294-6294
- IdRef : 033505187
Richard Dallier
- Fonction : Auteur
- PersonId : 21330
- IdHAL : richard-dallier
- ORCID : 0000-0001-9452-4849
- IdRef : 120243997
Pascal Lautridou
- Fonction : Auteur
- PersonId : 177535
- IdHAL : pascal-lautridou
- ORCID : 0000-0001-8473-6303
- IdRef : 079097405
Lilian Martin
- Fonction : Auteur
- PersonId : 1072
- IdHAL : lilian-martin
- ORCID : 0000-0002-9781-2632
- IdRef : 164855645
Benoît Revenu
- Fonction : Auteur
- PersonId : 3476
- IdHAL : benoit-revenu
- ORCID : 0000-0002-7629-4805
- IdRef : 068687893
Imen Al Samarai
- Fonction : Auteur
- PersonId : 7760
- IdHAL : imen-al-samarai
- IdRef : 164658653
Résumé
We present the results of an analysis of the large angular scale distribution of the arrival directions of cosmic rays with energy above 4 EeV detected at the Pierre Auger Observatory including for the first time events with zenith angle between $60^\circ$ and $80^\circ$. We perform two Rayleigh analyses, one in the right ascension and one in the azimuth angle distributions, that are sensitive to modulations in right ascension and declination, respectively. The largest departure from isotropy appears in the $E > 8$ EeV energy bin, with an amplitude for the first harmonic in right ascension $r_1^\alpha =(4.4 \pm 1.0){\times}10^{-2}$, that has a chance probability $P(\ge r_1^\alpha)=6.4{\times}10^{-5}$, reinforcing the hint previously reported with vertical events alone.