scholarly journals Ultrahigh-energy cosmic ray production by turbulence in gamma-ray burst jets and cosmogenic neutrinos

2016 ◽  
Vol 94 (2) ◽  
Author(s):  
Katsuaki Asano ◽  
Peter Mészáros
Keyword(s):  
Gamma Ray ◽  
Cosmic Ray ◽  
Ultrahigh Energy ◽  
Gamma Ray Burst

scholarly journals Interpreting correlated observations of cosmic rays and gamma-rays from Centaurus A with a proton blazar inspired model

2020 ◽  
Vol 500 (1) ◽  
pp. 1087-1094
Author(s):  
Prabir Banik ◽  
Arunava Bhadra ◽  
Abhijit Bhattacharyya
Keyword(s):  
Cosmic Rays ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
High Energy ◽  
Energy Scale ◽  
Electromagnetic Spectrum ◽  
Ultrahigh Energy ◽  
Large Area ◽  
Centaurus A

ABSTRACT The nearest active radio galaxy Centaurus (Cen) A is a gamma-ray emitter in GeV–TeV energy scale. The high energy stereoscopic system (HESS) and non-simultaneous Fermi–Large Area Telescope observation indicate an unusual spectral hardening above few GeV energies in the gamma-ray spectrum of Cen A. Very recently the HESS observatory resolved the kilo parsec (kpc)-scale jets in Centaurus A at TeV energies. On the other hand, the Pierre Auger Observatory (PAO) detects a few ultrahigh energy cosmic ray (UHECR) events from Cen-A. The proton blazar inspired model, which considers acceleration of both electrons and hadronic cosmic rays in active galactic nuclei (AGN) jet, can explain the observed coincident high-energy neutrinos and gamma-rays from Ice-cube detected AGN jets. Here, we have employed the proton blazar inspired model to explain the observed GeV–TeV gamma-ray spectrum features including the spectrum hardening at GeV energies along with the PAO observation on cosmic rays from Cen-A. Our findings suggest that the model can explain consistently the observed electromagnetic spectrum in combination with the appropriate number of UHECRs from Cen A.

scholarly journals Ultrahigh-energy diffuse gamma-ray emission from cosmic-ray interactions with the medium surrounding acceleration sources

2022 ◽  
Vol 105 (2) ◽  
Author(s):  
Pei-pei Zhang ◽  
Bing-qiang Qiao ◽  
Qiang Yuan ◽  
Shu-wang Cui ◽  
Yi-qing Guo
Keyword(s):  
Gamma Ray ◽  
Cosmic Ray ◽  
Ultrahigh Energy ◽  
Cosmic Ray Interactions ◽  
Gamma Ray Emission

scholarly journals Modeling the spectrum and composition of ultrahigh-energy cosmic rays with two populations of extragalactic sources

2021 ◽  
Vol 81 (1) ◽  
Author(s):  
Saikat Das ◽  
Soebur Razzaque ◽  
Nayantara Gupta
Keyword(s):  
Population Model ◽  
Gamma Ray ◽  
Statistical Significance ◽  
Cosmic Ray ◽  
Source Population ◽  
Ultrahigh Energy ◽  
Fermi Acceleration ◽  
Evolution Parameter ◽  
Best Fit ◽  
Two Populations

AbstractWe fit the ultrahigh-energy cosmic-ray (UHECR, $$E\gtrsim 0.1$$ E ≳ 0.1 EeV) spectrum and composition data from the Pierre Auger Observatory at energies $$E\gtrsim 5\cdot 10^{18}$$ E ≳ 5 · 10 18 eV, i.e., beyond the ankle using two populations of astrophysical sources. One population, accelerating dominantly protons ($$^1$$ 1 H), extends up to the highest observed energies with maximum energy close to the GZK cutoff and injection spectral index near the Fermi acceleration model; while another population accelerates light-to-heavy nuclei ($$^4$$ 4 He, $$^{14}$$ 14 N, $$^{28}$$ 28 Si, $$^{56}$$ 56 Fe) with a relatively low rigidity cutoff and hard injection spectrum. A significant improvement in the combined fit is noted as we go from a one-population to two-population model. For the latter, we constrain the maximum allowed proton fraction at the highest-energy bin within 3.5$$\sigma $$ σ statistical significance. In the single-population model, low-luminosity gamma-ray bursts turn out to match the best-fit evolution parameter. In the two-population model, the active galactic nuclei is consistent with the best-fit redshift evolution parameter of the pure proton-emitting sources, while the tidal disruption events could be responsible for emitting heavier nuclei. We also compute expected cosmogenic neutrino flux in such a hybrid source population scenario and discuss possibilities to detect these neutrinos by upcoming detectors to shed light on the sources of UHECRs.

scholarly journals PeV–EeV Neutrinos from Gamma-Ray Blazars due to Ultrahigh-energy Cosmic-Ray Propagation

2021 ◽  
Vol 910 (2) ◽  
pp. 100
Author(s):  
Saikat Das ◽  
Nayantara Gupta ◽  
Soebur Razzaque
Keyword(s):  
Gamma Ray ◽  
Cosmic Ray ◽  
Ultrahigh Energy
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