Seminarium odbywa się w środy o 11:15 w warszawskim oddziale Centrum Astronomicznego lub w wersji online na platformie Zoom. Językiem wykładowym jest angielski; seminarium prowadzi dr Stanisław Bajtlik (bajtlik@camk.edu.pl). Zapraszamy również osoby spoza Centrum Astronomicznego. W sprawie szczegółów technicznych prosimy kontaktować się e-mailowo z dr. Stanisławem Bajtlikiem.
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
Journal Club odbywa się w poniedziałki o 11:00 w Sali Seminaryjnej warszawskiego Centrum Astronomicznego. Językiem wykładowym jest angielski; spotkania prowadzą Angelos Karakonstantakis, Gergely Hajdu i Fatemeh Kayanikhoo.