Case for Centaurus A as the main source of ultrahigh-energy cosmic rays

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A90232%2F24%3A00641989" target="_blank" >RIV/68378271:90232/24:00641989 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1103/PhysRevD.110.063030" target="_blank" >https://doi.org/10.1103/PhysRevD.110.063030</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevD.110.063030" target="_blank" >10.1103/PhysRevD.110.063030</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Case for Centaurus A as the main source of ultrahigh-energy cosmic rays

Popis výsledku v původním jazyce

We discuss the possibility that a dominant fraction of the cosmic rays above the ankle (i.e., above 5 EeV) is due to a single nearby source, considering in particular the radio galaxy Centaurus A. We focus on the properties of the source spectrum and composition required to reproduce the observations, showing that the nuclei are strongly suppressed for E>10Z EeV, either by a rigidity dependent source cutoff or by the photodisintegration interactions with the cosmic microwave background at the giant dipole resonance. The very mild attenuation effects at lower energies imply that the secondary nuclei from this source, produced in photodisintegration processes during propagation, only provide a small contribution. Given the moderate anisotropies observed, the deflections in extragalactic and Galactic magnetic fields should play a crucial role in determining the cosmic ray arrival direction distribution. The diffusion in extragalactic fields as well as the finite source lifetime also significantly affect the shape of the observed spectrum. The cosmic ray flux at tens of EeV is dominated by the CNO component, and we show that it is actually better reproduced by a mixture of C and O nuclei rather than by the usual assumption of a N component effectively describing this mass group. The Si and Fe group components become dominant above 70 EeV, in the energy range in which a strong spectral suppression is present. If the localized flux excess appearing above 40 EeV around the Centaurus A direction is attributed to the CNO component, the He nuclei from the source in the energy range from 10 to 20 EeV could lead to a similar anisotropy unless its contribution is suppressed. The cosmic ray flux at a few EeV should mostly result from a more isotropic light component associated to a population of extragalactic sources. The inclusion of the subdominant contribution of heavy nuclei from the Galactic component helps to reproduce the observations around 1 EeV.

Název v anglickém jazyce

Case for Centaurus A as the main source of ultrahigh-energy cosmic rays

Popis výsledku anglicky

We discuss the possibility that a dominant fraction of the cosmic rays above the ankle (i.e., above 5 EeV) is due to a single nearby source, considering in particular the radio galaxy Centaurus A. We focus on the properties of the source spectrum and composition required to reproduce the observations, showing that the nuclei are strongly suppressed for E>10Z EeV, either by a rigidity dependent source cutoff or by the photodisintegration interactions with the cosmic microwave background at the giant dipole resonance. The very mild attenuation effects at lower energies imply that the secondary nuclei from this source, produced in photodisintegration processes during propagation, only provide a small contribution. Given the moderate anisotropies observed, the deflections in extragalactic and Galactic magnetic fields should play a crucial role in determining the cosmic ray arrival direction distribution. The diffusion in extragalactic fields as well as the finite source lifetime also significantly affect the shape of the observed spectrum. The cosmic ray flux at tens of EeV is dominated by the CNO component, and we show that it is actually better reproduced by a mixture of C and O nuclei rather than by the usual assumption of a N component effectively describing this mass group. The Si and Fe group components become dominant above 70 EeV, in the energy range in which a strong spectral suppression is present. If the localized flux excess appearing above 40 EeV around the Centaurus A direction is attributed to the CNO component, the He nuclei from the source in the energy range from 10 to 20 EeV could lead to a similar anisotropy unless its contribution is suppressed. The cosmic ray flux at a few EeV should mostly result from a more isotropic light component associated to a population of extragalactic sources. The inclusion of the subdominant contribution of heavy nuclei from the Galactic component helps to reproduce the observations around 1 EeV.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10303 - Particles and field physics

Projekt

—

Návaznosti

—

Rok uplatnění

2024

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physical Review D

ISSN

2470-0010

e-ISSN

2470-0029

Svazek periodika

110

Číslo periodika v rámci svazku

6

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

22

Strana od-do

063030

Kód UT WoS článku

001317463100003

EID výsledku v databázi Scopus

2-s2.0-85204437090