We review basic constraints on the acceleration of ultra-high-energy (UHE) cosmic rays (CRs) in astrophysical sources, namely, the geometrical (Hillas) criterion and the restrictions from radiation losses in different acceleration regimes. Using the latest available astrophysical data, we redraw the Hillas plot and find potential UHECR accelerators. For the acceleration in central engines of active galactic nuclei, we constrain the maximal UHECR energy for a given black hole mass. Among active galaxies, only the most powerful ones, radio galaxies and blazars, are able to accelerate protons to UHE, though acceleration of heavier nuclei is possible in much more abundant lower-power Seyfert galaxies.

PACS: 98.54.−h, 98.62.En, 98.70.Sa (all) DOI: 10.3367/UFNe.0180.201007c.0723 URL: https://ufn.ru/en/articles/2010/7/c/ 000282808100003 2-s2.0-77958531654 2010PhyU...53..691P Citation: Ptitsyna K V, Troitsky S V "Physical conditions in potential accelerators of ultrahigh energy cosmic rays: updated Hillas plot and radiation-loss constraints" Phys. Usp. 53 691–701 (2010) BibTexBibNote ® (generic) BibNote ® (RIS)MedlineRefWorks TY JOUR TI Physical conditions in potential accelerators of ultrahigh energy cosmic rays: updated Hillas plot and radiation-loss constraints AU Ptitsyna, K. V. AU Troitsky, S. V. PB Physics-Uspekhi PY 2010 JO Physics-Uspekhi JF Physics-Uspekhi JA Phys. Usp. VL 53 IS 7 SP 691-701 UR https://ufn.ru/en/articles/2010/7/c/ ER https://doi.org/10.3367/UFNe.0180.201007c.0723 Оригинал: Птицына К В, Троицкий С В «Физические условия в потенциальных ускорителях космических лучей сверхвысоких энергий: обновлённая диаграмма Хилласа и ограничения из потерь на излучение» УФН 180 723–734 (2010); DOI: 10.3367/UFNr.0180.201007c.0723