Exploring potential cosmic ray accelerators with neutrinos What do we learn by injecting nuclei in Gamma-Ray Bursts? Denise Boncioli, Daniel Biehl, Anatoli Fedynitch, Walter Winter DESY Zeuthen, Germany denise.boncioli@desy.de PoS(ICRC2017)1064
Cosmic-ray horizon from theory from data arXiv:1705.03729 [astro-ph.HE], submitted to JCAP Aloisio, Boncioli, di Matteo, Grillo, Petrera, Salamida, > No information about sources above z~1 ! > Can neutrinos be used to test UHECR sources ? The Pierre Auger Collaboration, ICRC2015 Denise Boncioli | Neutrinos and UHECRs | ICRC 2017 | Page 2
The role of neutrinos > Main UHECR processes (energy of the photon in the nucleus rest frame): - ε´>150 MeV, photo-pion production (nucleons and nuclei) - ε´> 8 MeV, photo-disintegration (nuclei) > Contributions to neutrino production: - pion decay - beta decay Denise Boncioli | Neutrinos and UHECRs | ICRC 2017 | Page 3
From the sources to detection Neutrino production happens both in the source and in the propagation through extragalactic space! Denise Boncioli | Neutrinos and UHECRs | ICRC 2017 | Page 4
Gamma-Ray Bursts as test case → shocks (single collision internal shock model) → particle acceleration (including nuclei !) → nuclear cascade (production of secondary nuclei and neutrinos) Denise Boncioli | Neutrinos and UHECRs | ICRC 2017 | Page 5 Credit: NASA
Nuclear cascade in a GRB shell Ejected fluences Pure iron ( 56 Fe) composition injected into a GRB shell ● Ejected fluence ● → dependent on the escape mechanisms (for charged CRs) → dependent on the density of the radiation Collisions at large radius and/or low luminosity GRB → rarefied photon field → less ➢ interactions Denise Boncioli | Neutrinos and UHECRs | ICRC 2017 | Page 6 Biehl, Boncioli, Fedynitch, Winter, arxiv:1705.08909, submitted to A&A
Nuclear cascade source classes: parameter space scan > Pure iron ( 56 Fe) composition injected into a GRB shell Denise Boncioli | Neutrinos and UHECRs | ICRC 2017 | Page 7 Biehl, Boncioli, Fedynitch, Winter, arxiv:1705.08909, submitted to A&A
Source – Propagation Model OUTPUT propagation source ➔ UHECR spectrum at Earth ➔ Composition observables ➔ Neutrino fluxes ➔ Produced in the source ➔ Produced during propagation INPUT INPUT Many uncertainties > Chemical composition > Distribution of sources affect the of accelerated CRs interpretation of the > Spectra of background > Spectrum of data ! photons accelerated CRs • Batista, Boncioli, di Matteo, van Vliet, > Photon spectrum in Walz, JCAP 1510 (2015) no.10, 063 > Nuclear Physics • Boncioli, Fedynitch, Winter, Scientific the source Reports 7, 4882 (2017) > Interaction model in • Pierre Auger Collaboration, JCAP 1704 > Nuclear Physics (2017) no.04, 038 the Earth’s > Escape mechanism Nuclear Physics and UHECR interactions: atmosphere Fedynitch, Boncioli, Winter, for CRs Poster at CRI session , PoS(2017)559 Denise Boncioli | Neutrinos and UHECRs | ICRC 2017 | Page 8
Source – Propagation Model Biehl, Boncioli, Fedynitch, Winter, arxiv:1705.08909, submitted to A&A Fit of UHECR data above 10 EeV → excluding the ankle pure Si at injection Extragalactic propagation → SimProp MC code First release: Aloisio, Boncioli, Grillo, Petrera, Salamida, JCAP 1210 (2012) 007 Last release: Aloisio, Boncioli, di Matteo, Grillo, Petrera, Salamida, arXiv:1705.03729 [astro-ph.HE], submitted to JCAP Denise Boncioli | Neutrinos and UHECRs | ICRC 2017 | Page 9
Source – Propagation Model Biehl, Boncioli, Fedynitch, Winter, arxiv:1705.08909, submitted to A&A Fit of UHECR data above 10 EeV → excluding the ankle pure Si at injection IceCube excluded region from GRB stacking analysis , Aartsen et al 2017 Extragalactic propagation → SimProp MC code First release: Aloisio, Boncioli, Grillo, Petrera, Salamida, JCAP 1210 (2012) 007 Last release: Aloisio, Boncioli, di Matteo, Grillo, Petrera, Salamida, arXiv:1705.03729 [astro-ph.HE], submitted to JCAP Denise Boncioli | Neutrinos and UHECRs | ICRC 2017 | Page 10
Source – Propagation Model Biehl, Boncioli, Fedynitch, Winter, arxiv:1705.08909, submitted to A&A Fit of UHECR data above 10 EeV → excluding the ankle pure Si at injection IceCube excluded region IceCube excluded region from cosmogenic neutrinos , from GRB stacking Aartsen et al 2016 analysis , Aartsen et al 2017 Extragalactic propagation → SimProp MC code First release: Aloisio, Boncioli, Grillo, Petrera, Salamida, JCAP 1210 (2012) 007 Last release: Aloisio, Boncioli, di Matteo, Grillo, Petrera, Salamida, arXiv:1705.03729 [astro-ph.HE], submitted to JCAP Denise Boncioli | Neutrinos and UHECRs | ICRC 2017 | Page 11
“Mixed Composition Ankle Model” A=1 A=[2,4] A=[5,22] A=[22,28] pure Si at injection Fit above 10 EeV → excluding the ankle Denise Boncioli | Neutrinos and UHECRs | ICRC 2017 | Page 12 Biehl, Boncioli, Fedynitch, Winter, arxiv:1705.08909, submitted to A&A
Summary > We take into account the injection of nuclei (→ results from Pierre Auger Observatory about chemical composition) in Gamma-Ray Bursts and model the interactions in the source > Neutrino and CR production depend on the development of the cascade in the source → classification of sources in terms of population of the cascade → importance of uncertainties (from nuclear physics and astrophysics) - Boncioli, Fedynitch, Winter, Scientific Reports 7, 4882 (2017) - A. Fedynitch, Poster at CRI session, PoS(2017)559 > Ejected fluxes of CRs and neutrinos from the source are propagated to Earth → source-propagation model, including a fit of UHECR data > Neutrinos can efficiently test the GRB-UHECR paradigm ! - Boncioli, Biehl, Fedynitch, Winter, PoS(ICRC2017)1064 - Biehl, Boncioli, Fedynitch, Winter, arxiv:1705.08909, submitted to A&A Denise Boncioli | Neutrinos and UHECRs | ICRC 2017 | Page 13
Future directions > Efficient combined source-propagation model → can be applied to other candidate sources, such as Active Galactic Nuclei → can be applied to other models for GRBs, such as multi-zone > More detailed parameter-space study including → variations in the propagation (EBL model, cross section model) → variations in the hypotheses at the sources (source distribution and evolution with redshift, mixed composition at the source, spectrum function at injection) - Boncioli, Biehl, Fedynitch, Winter, PoS(ICRC2017)1064 - Biehl, Boncioli, Fedynitch, Winter, arxiv:1705.08909, submitted to A&A Denise Boncioli | Neutrinos and UHECRs | ICRC 2017 | Page 14
BACKUP slides Denise Boncioli | Neutrinos and UHECRs | ICRC 2017 | Page 15
> Talk by D. Biehl at Injection of nuclei and maximum energy Neucos Workshop > Injection of nuclei with cut-off power law spectrum expected from Fermi shock acceleration in acceleration zone Here: k = 2 P = 2 > Maximum energy reached when the sum of all energy loss processes exceeds the energy gain by the acceleration Pair prod. typically sub-dom. here > Normalization to injection luminosity with “nuclear loading” Denise Boncioli | Neutrinos and UHECRs | ICRC 2017 | Page 16
Interactions Boltzmann Equations for each particle species (and energy bin) Boltzmann Equations for each particle species (and energy bin) Escape: Escape: Evolution of density Energy loss: Evolution of density Energy loss: dynamical timescale dynamical timescale for particle species i synchrotron for particle species i synchrotron interactions interactions adiabatic adiabatic decays decays … … Injection from: Injection from: … … acceleration zone acceleration zone interactions or decays interactions or decays Q ν ,out Radiation Beam of p, A, zone: … Q A’,out A p , A γ Interactio ns Q γ ,out Denise Boncioli | Neutrinos and UHECRs | ICRC 2017 | Page 17
Energetics of the source > Spectrum of GRBs: > Isotropic volume: > Normalization of the photon flux Denise Boncioli | Neutrinos and UHECRs | ICRC 2017 | Page 18
GRB models > Internal shock model (one-zone): the shells of plasma are assumed to collide at and the shell width is The collisions happen at the same radius > Internal shock model (multi-zone): (Kobayashi, Piran and Sari (1997)) shells of plasma are ejected from the central emitter, colliding at varying collision radii centered around a mean value. The key parameter is R > Photospheric models, for example in Rees and Meszaros (2005) > Magnetic reconnection models, for example in Zhang and Yan (2011) Denise Boncioli | Neutrinos and UHECRs | ICRC 2017 | Page 19
Cosmic ray escape > Neutrons can escape freely while charged particles can only escape if they can reach the edge of the shell within their Larmor radius: > The condition is satisfied if the maximal primary energy is limited by the adiabatic energy losses (typically when the radiation densities and the primary energies are low) > Direct escape will be suppressed if the source is optically thick to photo-hadronic interactions > Discussed in Baerwald et al (2013); the mechanism of escape affects the CR:neutrino ratio Denise Boncioli | Neutrinos and UHECRs | ICRC 2017 | Page 20
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