Correlation of the UHECR with AGN using the new statistical test methods and the updated data from Pierre Auger Observatory Hang Bae Kim (Hanyang Univ.) Collaboration with J.H. Kim TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.: A A A AA A A A A AA A A ICRC 2011, Beijing

UHECR Source Hunting  Confirmation of GZK suppression in the CR energy spectrum UHECR with E > E GZK ¼ 4x10 19 eV mostly come from relatively close (d < r GZK ¼ 100 Mpc) extragalactic sources. UHECR with E > E GZK ¼ 4x10 19 eV mostly come from relatively close (d < r GZK ¼ 100 Mpc) extragalactic sources. Arrival directions of UHECR keep some correlation with the source distribution. Assumption : The intergalactic magnetic fields are not so strong that they don’t alter significantly the trajectories of UHECR with these high energies.  Why statistical analysis? Source identification of individual UHECR is quite difficult yet. No. of candidate sources is much larger than No. of UHECR events.

Arrival Direction Analysis Experiment Modeling Observed AD Distribution Expected AD Distribution Statistical Comparison Probability that the observed distribution is obtained from the expected distribution Test Methods Multipole moments, 2D KS, … KS on the reduced 1D distribution Test Methods Multipole moments, 2D KS, … KS on the reduced 1D distribution Astrophysical Sources Dark Matter Decay Astrophysical Sources Dark Matter Decay Simulation

Exposure Function The detector array does not cover the sky uniformly and we must consider its efficiency as a function of the arrival direction. Here we consider only the geometrical efficiency.

Example: RA, DEC Distribution 2D Distribution 1D Distribution Observed Data (PAO, E≥55 EeV ) Simulation Data (Isotropic) RA Distribution DEC Distribution

Kolmogorov-Smirnov Test Comparison of two one-dimensional probability distributions Kolmogorov-Smirnov (KS) statistic Probability that the observed distribution is obtained from the expected distribution Cumulative probability distribution KS statistic

Auto-Angular Distance Dist. (AADD) clusteredisotropic Distribution of the angular distances of all paris of UHECR ADs

Distribution of the angular distances of all paris of UHECR and the point sources Correl. Angular Distance Dist. (CADD) correlatedisotropic

Distribution of the expected flux values at UHECR arrival directions Flux-Exposure Value Dist. (FEVD) isotropic flux-following

Simple AGN Model  Selection of UHECR Energy cut We take  Selection of AGN Distance cut We take  Hypothesis : UHECRs are composed of two components AGN contribution - fraction f Background (isotropic) contribution - fraction 1-f  Notes The fraction f depends on E c and d c. For uniform source distribution, PAO-AGN

 UHECR flux from AGN For simplicity, we assume the universality of AGN: L j =L, θ sj =θ s  Expected flux Two parameters : AGN contribution fraction f, Isotropic component fraction 1-f, Simple AGN Model UHECR Luminosity Distance Smearing Simulation of the simple AGN model with f=1, θ s =6 ° for PAO.

PAO-AGN-CADD The cumulative probability distribution of CADD using the AGN reference set  Steep rise of CPD near µ =0 means the strong correlation at small angles.  PAO data looks more correlated with AGNs than isotropic distribution.  PAO data are not consistent with the hypothesis that they are completely originated from AGNs.  Adding isotropic (background) component can make the consistency improved.

 More correlation with AGN than simple isotropy  Complete AGN origination is also ruled out.  Adding isotropic component makes the AGN model more plausible.  Correlation got weaker for PAO data released in Correlation with AGN PAO

Restricting the sources …  Number of AGN (Sources) >> Number of UHECR  Fine classification of AGN may be need. – Physical properties and/or Environments  Distance Binning – No physical motivation, but …

Summary  We developed the statistical methods for the comparison of two HUECR AD distributions: AADD, CADD, FEVD, … Isotropy Correlation with point sources  Test of UHECR–AGN correlation The simple AGN model AGN contribution + Isotropic background Two parameters : AGN fraction, Smearing angle Data UHECR : 2010 PAO data, AGN : 13 th Ed. of VCV catalog AGN domination with a small smearing angle is ruled out.  UHECR source hunting must be continued.