Testing astrophysical model to interpret the Auger data PhD - PowerPoint PPT Presentation

Testing astrophysical model to interpret the Auger data PhD candidate: Antonio Condorelli Supervisors: Sergio Petrera, Denise Boncioli Admission to the third year, 
 GSSI, 17th October 2019

Outline Restyling of the Combined fit; Application to a mass composition study; Interpretation of the ankle feature; Source effect mechanism; Conclusion and future perspectives; A.Condorelli Testing astrophysical model to interpret Auger data 2

Auger 
 spectrum • What is the origin of the cosmic-ray features in the energy spectrum? • Energy spectrum alone remains ambiguous concerning interpretation. V.Verzi [PierreAugerColl.], PoS(ICRC2019)450 A.Condorelli Testing astrophysical model to interpret Auger data 3

Combined fit of both spectrum and composition A. Aab et al .,JCAP04(2017)038,arXiv:1612.07155v3 A.Condorelli Testing astrophysical model to interpret Auger data 4

Update of the combined fit A.Condorelli Testing astrophysical model to interpret Auger data 5

Update of the combined fit Working principle of the combined fit A.Condorelli Testing astrophysical model to interpret Auger data 6

Update of the combined fit Working principle of the fraction fit A.Condorelli Testing astrophysical model to interpret Auger data 7

Update of the combined fit t a d ! e 9 t 1 n 0 e 2 s e C r R P C I Working principle of the fraction fit A.Yushkov [PierreAugerColl.], PoS(ICRC2019)482 A.Condorelli Testing astrophysical model to interpret Auger data 8

Results of fraction fit EPOS-LHC - Gumbel 1 17.8 < lg(E/eV) < 17.9 17.9 < lg(E/eV) < 18.0 18.0 < lg(E/eV) < 18.1 18.1 < lg(E/eV) < 18.2 H 0.16 0.9 0.16 D/N = 43.7/23 D/N = 64.7/25 D/N = 31.6/26 D/N = 35.5/24 0.16 0.16 0.14 0.14 0.8 0.14 0.14 0.12 0.12 0.7 0.12 0.12 0.1 0.1 0.1 0.6 0.1 0.08 0.08 0.08 0.08 0.5 0.06 0.06 0.06 0.06 0.4 0.04 0.04 0.04 0.04 0.3 0.02 0.02 0.02 0.02 0.2 0 0 0 0 500 600 700 800 900 1000 500 600 700 800 900 1000 500 600 700 800 900 1000 1100 600 700 800 900 1000 1100 -2 -2 -2 -2 0.1 X [g cm ] X [g cm ] X [g cm ] X [g cm ] max max max max 0 17 17.5 18 18.5 19 19.5 18.2 < lg(E/eV) < 18.3 18.3 < lg(E/eV) < 18.4 18.4 < lg(E/eV) < 18.5 18.5 < lg(E/eV) < 18.6 0.18 0.2 D/N = 32.6/24 D/N = 23.7/22 D/N = 15.8/20 D/N = 32.6/22 0.16 0.18 0.16 0.18 0.14 0.16 0.14 0.16 0.14 0.12 1 0.12 0.14 0.12 0.1 He 0.12 0.9 0.1 0.1 0.1 0.08 0.08 0.8 0.08 0.08 0.06 0.06 0.06 0.06 0.7 0.04 0.04 0.04 0.04 0.6 0.02 0.02 0.02 0.02 0.5 0 0 0 0 500 600 700 800 900 1000 1100 600 700 800 900 1000 1100 600 700 800 900 1000 600 700 800 900 1000 1100 -2 -2 -2 -2 X [g cm ] X [g cm ] X [g cm ] X [g cm ] max max max max 0.4 0.3 18.6 < lg(E/eV) < 18.7 18.7 < lg(E/eV) < 18.8 18.8 < lg(E/eV) < 18.9 18.9 < lg(E/eV) < 19.0 0.2 0.22 0.25 D/N = 31.8/19 D/N = 11.0/15 D/N = 14.6/16 D/N = 31.4/15 0.2 0.2 0.25 0.1 0.18 0.18 0.2 0 0.16 0.16 0.2 17 17.5 18 18.5 19 19.5 0.14 0.14 0.15 0.12 0.12 0.15 0.1 0.1 0.1 0.08 0.08 0.1 1 0.06 0.06 0.05 N 0.04 0.04 0.05 0.9 0.02 0.02 0.8 0 0 0 0 600 700 800 900 1000 1100 600 650 700 750 800 850 900 950 1000 600 650 700 750 800 850 900 950 1000 700 800 900 1000 1100 -2 -2 -2 -2 X [g cm ] X [g cm ] X [g cm ] X [g cm ] max max max max 0.7 0.6 19.0 < lg(E/eV) < 19.1 19.1 < lg(E/eV) < 19.2 19.2 < lg(E/eV) < 19.3 19.3 < lg(E/eV) < 19.4 0.5 0.4 D/N = 18.0/13 D/N = 26.3/12 0.3 D/N = 11.7/12 D/N = 24.9/9 0.25 0.3 0.4 0.35 0.25 0.25 0.3 0.2 0.3 0.2 0.2 0.2 0.25 0.15 0.1 0.15 0.2 0.15 0.1 0.15 0 0.1 0.1 17 17.5 18 18.5 19 19.5 0.1 0.05 0.05 0.05 0.05 0 0 0 0 650 700 750 800 850 900 950 1000 650 700 750 800 850 900 950 1000 650 700 750 800 850 900 950 1000 650 700 750 800 850 900 950 1000 -2 -2 -2 -2 X [g cm ] X [g cm ] X [g cm ] X [g cm ] max max max max 1 Fe 0.9 19.4 < lg(E/eV) < 19.5 19.5 < lg(E/eV) < 21.0 0.3 0.8 0.4 D/N = 16.8/9 D/N = 3.3/8 0.7 0.35 0.25 0.3 0.6 0.2 0.25 0.5 0.15 0.2 0.4 0.15 0.1 0.3 0.1 0.2 0.05 0.05 0.1 0 0 700 750 800 850 900 950 700 750 800 850 900 0 -2 -2 X [g cm ] X [g cm ] max max 17 17.5 18 18.5 19 19.5 A.Condorelli Testing astrophysical model to interpret Auger data 9

Testing source effect mechanism

Testing source effect mechanism

Auger measurements A.Condorelli Testing astrophysical model to interpret Auger data 12

What is the ankle? If we assume only proton spectrum—> feature of the propagation; Transition point between galactic and extragalactic cosmic rays; Two extragalactic components; Source mechanism; A.Condorelli Testing astrophysical model to interpret Auger data 13

Testing a model Consider a system in which the accelerator (also referred to as the source) is embedded in an environment in which the cosmic rays are confined by magnetic fields while interacting with the ambient radiation field. The lower the energy, the more time the nuclei have to interact before escaping, leading to a hardening of the spectrum and lightening of the composition of nuclei escaping the region surrounding the source. Origin of the ankle in the ultrahigh energy cosmic ray spectrum and of the extragalactic protons below it, M.Unger, G. Farrar, L. Anchordoqui, arXiv:1505.02153v2 A.Condorelli Testing astrophysical model to interpret Auger data 14

SimProp What ? MonteCarlo code for propagation of particle through the Universe; Generation of a primary (proton or nucleus) and its propagation from the source to the observer; Taking into account all possible energy losses; Why? Interaction time easy to compute; Propagation and production of secondary particles; Implementation of a generic photon field; A single code for propagation inside and outside the source; SimProp v2r4: Monte Carlo simulation code for UHECR propagation, R.Aloisio, D.Boncioli, A.Di Matteo, A.F. Grillo, S.Petrera, F.Salamida , arXiv:1705.03729 . A.Condorelli Testing astrophysical model to interpret Auger data 15

Interaction and escape time Photodisintegration Photomeson Total The shape of the spectrum of the target photons is needed. The interaction time is given by the double integral on the cross sections and on the photon field; The escaping time is just a power law on rigidity. A.Condorelli Testing astrophysical model to interpret Auger data 16

H He N Si Fe A.Condorelli Testing astrophysical model to interpret Auger data 17

Ejected Spectra dN/dlogE [a.u.] 6 10 5 10 4 10 3 10 2 10 17.5 18 18.5 19 19.5 20 20.5 log10(E)[eV] Origin of the ankle in the ultrahigh energy cosmic ray spectrum and of the extragalactic protons below it, M.Unger, G. Farrar, L. Anchordoqui, arXiv:1505.02153v2 A.Condorelli Testing astrophysical model to interpret Auger data 18

Neutrino spectrum from the source Neutrinos 8 10 dN/dlogE [a.u.] Legenda Standard configuration 7 10 low T 6 10 Decreasing temperature by a factor 10 5 10 4 10 3 10 Neutrinos 8 10 dN/dlogE [a.u.] Legenda 8 10 12 14 16 18 log10(E)[eV] Standard configuration 7 10 High Luminosity 6 10 5 Increasing luminosity by a factor 10 10 4 10 3 10 8 10 12 14 16 18 log10(E)[eV] A.Condorelli Testing astrophysical model to interpret Auger data 19

Application of source mechanism to SBGs Cosmic ray transport and radiative processes in nuclei of starburst galaxies, E.Peretti, P .Blasi, F.Aharonian, G.Morlino. arXiv:1812.01996v2 A.Condorelli Testing astrophysical model to interpret Auger data 20

Summary and future perspectives Tools Organizing combined fit code according to a logic structure and applications; Fit using two components. Source mechanism A single code for propagation inside and outside the source; How the neutrino flux (produced in the source) changes according to the source 
 parameters —> Additional observables with respect to cosmogenic neutrinos. Studying of parameter space for real sources; Studying of the diffusion process inside the source; Development of simplified analytical approach; Interpretation Fit at the source. A.Condorelli Testing astrophysical model to interpret Auger data 21

Summary and future perspectives Tools Organizing combined fit code according to a logic structure and applications; Fit using two components. Source mechanism A single code for propagation inside and outside the source; How the neutrino flux (produced in the source) changes according to the source 
 parameters —> Additional observables with respect to cosmogenic neutrinos. Studying of parameter space for real sources; Studying of the diffusion process inside the source; Development of simplified analytical approach; Interpretation combined fit Source mechanism Fit at the source. A.Condorelli Testing astrophysical model to interpret Auger data 22

s e d i l s p u - k c a b A.Condorelli Testing astrophysical model to interpret Auger data 23

Assumptions A.Condorelli Testing astrophysical model to interpret Auger data 24