Recent Results from the KASCADE-Grande Data Analysis

Transcription

1 Recent Results from the KASCADE-Grande Data Analysis Donghwa Kang for the KASCADE-Grande Collaboration Karlsruhe Institute of Technology 20 th ISVHECRI May 2018, Nagoya, Japan

2 Status & Prospect KASCADE + KASCADE-Grande: - Successfully completed data acquisition at the end of Now dismantled - Detectors (partly) are used elsewhere 2015 Detailed data analysis with 20 years high quality data: - Combined analysis for coherent spectrum and composition ev - Testing hadronic interaction models (SIBYLL 2.3c) - Muon attenuation length and CR composition (Poster ID 25 by Juan Carlos) - Limits on diffuse gamma-ray flux - Anisotropy studies KCDC KASCADE Cosmic ray Data Center 2

3 Combined Analysis KASCADE and KASCADE-Grande [Dissertation of Sven Schoo] 3

4 Shower reconstruction from the events measured by both arrays with an extension of the fiducial area For KASCADE: additional stations at larger distances higher energies For Grande: additional 252 stations higher accuracy Accuracy of electron and muon numbers improves more than 5 10% 4

5 2-dim shower size spectrum obtained by the combined shower reconstruction determination of primary energy Zenith angle up to 30 k-parameter: normalized shower size ratio k=0 (proton) and k=1 (iron) Separation in light (H+He) and heavy (C+Si+Fe) components log 10 (E/GeV) = [a H + (a Fe a H )k]log 10 (N ch ) + b H +(b Fe b H )k k = (log 10 (N ch /N ) - log 10 (N ch /N ) H ) (log 10 (N ch /N ) Fe - log 10 (N ch /N ) H )

6 QGSJet-II-04 SIBYLL 2.3 All Light (H+He) Heavy (C+Si+Fe) All Light (H+He) Heavy (C+Si+Fe) EPOS-LHC All Light (H+He) Heavy (C+Si+Fe) Reconstructed energy spectra obtained with different interaction models All structures confirmed and relative abundance of light and heavy quite different Reconstruction correction (unfolding) not corrected yet 6

7 QGSJet-II-04 vs EPOS-LHC Obtained with post-lhc models Structure confirmed Light primary interactions okay Heavy primary interactions show differences with increasing energy Muon component not sufficiently described (Distance from shower core covered by muon detectors limited) [Paper in preparation] 7

8 Testing Hadronic Interaction Model (SIBYLL 2.3c) Based on Shower Size [Advances in Space Research 53 (2014) ] [J. Phys.: Conf. Ser. 409 (2013) ]

9 2-dim. shower size spectrum, along with proton and iron induced showers for QGSJET-II-04, EPOS-LHC, SIBYLL 2.3 and SIBYLL 2.3c simulations

10 Relation between the number of charged particles Nch and the muon numbers N as a function of Nch for different simulations, including the full detector response by simulation.

11 threshold full efficiency Measured shower size spectra for different zenith angle bins Energy spectrum based on the shower size

12 Energy Calibration Linear fit: log 10 E true = p0 log 10 N ch + p1 Proton Iron p0 p1 p0 p1 SIBYLL 2.3c SIBYLL SIBYLL

13 All-particle Energy Spectrum Hardening (enhancement) of the spectrum for proton primary at higher energies Shower to shower fluctuations are not taken into account yet Total systematic uncertainties for proton and iron are expected less than 20% 13

14 All-particle Energy Spectrum a slight discrepancy of the spectral slopes due to different ratio of Nch/N all the spectra show a similar feature spectrum not a single power law different elemental composition in the transition region 14

15 Selecting Primary Mass Group SIBYLL 2.3c Individual spectra by attenuation corrected shower size ratio: Y CIC = lg(n,cf ) CIC / lg(n ch ) CIC Y CIC SIBYLL 2.3c SIBYLL SIBYLL SIBYLL 2.3 SIBYLL

16 Energy Calibration For electron-poor (heavy) and electron-rich (light) mass groups Heavy (electron-poor) Fit: log 10 E true = p0 log 10 N ch + p1 HEAVY LIGHT p0 p1 p0 p1 SIBYLL 2.3c SIBYLL SIBYLL

17 Spectra of Individual Mass Groups Knee-like structure of heavy primaries below ev Hardening of light primaries is significant Estimation of systematic uncertainties is ongoing 17

18 Spectra of Individual Mass Groups Shifted total energy fluxes Knee-like structure of heavy primaries and hardening of light primaries are similar Fit: ( E) K E 1 1 E E K 2 1 electron-poor lg(e k /GeV) /ndf SIBYLL SIBYLL SIBYLL 2.3c

19 Limits on Diffuse Gamma-ray Flux Motivation: What can be expected with full statistics of KASCADE and KASCADE- Grande data in the higher energy range?

20 -ray Selection KASCADE KASCADE-Grande The analysis is performed by selecting showers with low muon contents KASCADE: N=0, lg(ne) < 5.15 and lg(n) < 1.4 lg(ne) 5.21, lg(ne) > 5.15, Age < 1.0 KASCADE-Grande: N=0 for lg(nch) < 6.2, lg(n) < 1.64 lg(nch) 6.95 for lg(nch) > 6.2

21 Fraction of -rays Relative to Cosmic-rays 90% upper limits on ratio of primary gammas to hadrons: I γ I CR < N γ,90 N all ε γ E CR E γ β+1 ApJ 848 (2017) 1

22 Limits on Diffuse Gamma-ray Flux Comparison with previous results Constraints on the origin of IceCube neutrinos, i.e. reject the model of IceCube excess coming from < 20 kpc in the galaxy 22

23 KCDC (KASCADE Cosmic ray Data Centre) = publishing research data from the KASCADE experiment Motivation and Idea of Open Data: - general public has to be able to access and use the data - the data has to be preserved for future generations Web portal: - provide a modern software solution - release the software as Open Source - educational examples Data access: - latest release (Feb. 2017) with EAS events - simulation data - energy spectra of other experiments Pioneering work in publishing research data 23

24 98 published energy spectra of other experiments! 24

25 Summary Features of the energy spectrum confirmed by combined analysis of KASCADE and -Grande: First observation of a heavy knee at ev Flattening of the light component around ev Maybe the first sign of an extra-galactic component Validity of the hadronic interaction model SIBYLL 2.3c: Total energy flux is shifted, but all structures are similar. Using full data sets taken by KASCADE and -Grande, the 90% C.L. upper limits to diffuse -rays for energies of 200TeV 300PeV are determined by selecting showers with low muon contents. Obtained the best upper limit at 1.5 and 3.6 PeV Constrain on the IceCube excess model coming from < 20 kpc in the galaxy Pioneering work in public access of astroparticle physics data (KCDC) Towards a Global Data and Analysis Centre for Astroparticle Physics 25