Seminars

Wednesday Colloquium

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The Colloquium takes place every Wednesday at 11:15 AM - Warsaw Copernicus Astronomical Centre online by means of Zoom platform. The Colloquium is given in English and chaired by dr Stanisław Bajtlik (bajtlik@camk.edu.pl)People from outside of the Copernicus Center are very welcome to participate. For technical detailes please contact Dr. Stanislaw Bajtlik.



20.03.2024

"Binary coalescences as sources of ultrahigh-energy cosmic rays"

Jonas Pereira (Núcleo de Astrofísica e Cosmologia & Departamento de Física, Universidade Federal do Espírito Santo, Vitória, Brasil and CAMK, W)

Binary coalescences are known sources of gravitational waves (GWs) and they encompass combinations of black holes (BHs) and neutron stars (NSs). I’ll show that when BHs are embedded in magnetic fields (B’s) larger than approximately e10 G, charged particles colliding around their event horizons can easily have ultrahigh energies (≳ e18 eV) and become more likely to escape. Such B-embedding and high-energy particles can take place in BH-NS binaries, or even in BH-BH binaries with one of the BHs being charged (with charge-to-mass ratios as small as e-5, which do not change GW waveforms) and having a residual accretion disk. The number of collisions leading to ultrahigh energy particles is estimated to range from a few up to millions before the merger of binary compact systems. Thus, binary coalescences may also be efficient sources of ultrahigh energy cosmic rays (UHECRs) and constraints to NS/BH parameters would be possible if UHECRs are detected along with GWs.

The presentation will be based on recent PRL work: Binary Coalescences as Sources of Ultrahigh-Energy Cosmic Rays Jonas P. Pereira, Carlos H. Coimbra-Araújo, Rita C. dos Anjos, and Jaziel G. Coelho Phys. Rev. Lett. 132, 091401 – Published 27 February 2024


 


Special seminars

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Journal Club

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Journal Club takes place on Mondays at 11:00 AM in the Seminar Room. The seminar is given in English and is chaired by Angelos  Karakonstantakis, Gergely Hajdu, and Fatemeh Kayanikhoo.



 


The Bohdan Paczyński Memorial Colloquium

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GeoPlanet Seminars

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