%0 Journal Article
%A Rudolph, Annika
%A Bosnjak, Zeljka
%A Palladino, Andrea
%A Sadeh, Iftach
%A Winter, Walter
%T Multi-wavelength radiation models for low-luminosity GRBs, and the implications for UHECRs
%J Monthly notices of the Royal Astronomical Society
%V 511
%N 4
%@ 0035-8711
%C Oxford
%I Oxford Univ. Press
%M PUBDB-2021-02589
%M arXiv:2107.04612
%M DESY-21-103
%P 5823 – 5842
%D 2022
%X We study the prompt phase of low-luminosity Gamma-Ray Bursts (LL-GRBs) as potential source of very-high-energy (VHE) gamma rays and ultra-high-energy cosmic rays (UHECRs).We model the spectral energy distribution of three representative examples (with observed properties similar to GRBs 980425, 100316D and 120714B)  self-consistently in a leptonic synchrotron self-Compton (SSC) scenario using the internal shock model for the relativistic outflow. To investigate the conditions under which inverse Compton radiation may lead to a peak in the GeV-TeV range potentially observable in Imaging Atmospheric Cherenkov Telescopes (IACTs), we vary the fraction of the energy budget supplying the magnetic field. As a second step, we determine the maximal energies achievable for UHECR nuclei. Assuming LL-GRBs to power the observed UHECR flux, we derive constraints on the baryonic loading and typical GRB duration by explicitly calculating the contribution of LL-GRBs to the diffuse extragalactic gamma-ray background. We find that LL-GRBs are potential targets for multi-mavelength studies and may be in reach of current/ future IACTs and optical/ UV instruments.For comparable sub-MeV emission and similar jet properties, the multi-wavelength predictions show a strong dependence on the magnetic field: weak (strong) magnetic fields induce high (low) fluxes in the VHE regime and low (high) fluxes in the optical. However, VHE emission might be suppressed by γγ-absorption close to the source (especially for high magnetic fields) or interactions with the extragalactic background light for redshifts z  >  0.1.For UHECRs, we find that the maximal energies of iron nuclei (protons) can be as high as  ≅ 10<sup>11</sup> GeV (10<sup>10</sup> GeV) if the magnetic energy density is large (where we predict a weak VHE component). These high energies are possible by decoupling the production regions of UHECR and gamma-rays in our multi-zone model. Finally, we find basic consistency with the energy budget needed to accommodate the UHECR origin from LL-GRBs.
%K cosmic radiation: UHE (INSPIRE)
%K cosmic radiation: spectrum (INSPIRE)
%K gamma ray: burst (INSPIRE)
%K energy: internal (INSPIRE)
%K iron: nucleus (INSPIRE)
%K gamma ray: background (INSPIRE)
%K energy: high (INSPIRE)
%K magnetic field: high (INSPIRE)
%K energy: density (INSPIRE)
%K energy: magnetic (INSPIRE)
%K VHE (INSPIRE)
%K acceleration (INSPIRE)
%K optical (INSPIRE)
%K shock waves (INSPIRE)
%K messenger (INSPIRE)
%K spectral (INSPIRE)
%K energy spectrum (INSPIRE)
%K synchrotron (INSPIRE)
%K decoupling (INSPIRE)
%K redshift (INSPIRE)
%K Cherenkov counter: atmosphere (INSPIRE)
%K imaging (INSPIRE)
%K suppression (INSPIRE)
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000766832600012
%R 10.1093/mnras/stac433
%U https://bib-pubdb1.desy.de/record/459509