Autor(es)

Genaro, M. ; Pereira, L. A. Stuani ; Pimentel, D. R. de Matos ; Santos, E. Moura

• Tipo de documento: Artigo Científico
• Fonte: Journal of Cosmology and Astroparticle Physics; v. N/A, n. 3, p. 45-pg., 2024-03-01.

Resumo

The Extragalactic Background Light (EBL) is the main radiation field responsible for attenuating extragalactic gamma -ray emission at very high energies, but its precise spectral intensity is not fully determined. Therefore, disentangling propagation effects from the intrinsic spectral properties of gamma -ray sources (such as active galactic nuclei, AGN) is the primary challenge to interpret observations of these objects. We present a Bayesian and Markov Chain Monte Carlo approach to simultaneously infer parameters characterizing the EBL and the intrinsic spectra in a combined fit of a set of sources, which has the advantage of easily incorporating the uncertainties of both sets of parameters into one another through marginalization of the posterior distribution. Taking a sample of synthetic blazars observed by the ideal CTA configuration, we study the effects on the EBL constraints of combining multiple observations and varying their exposure. We also apply the methodology to a set of 65 gamma -ray spectra of 36 different AGNs measured by current Imaging Atmospheric Cherenkov Telescopes, using Hamiltonian Monte Carlo as a solution to the difficult task of sampling in spaces with a high number of parameters. We find robust constraints in the mid-IR region while simultaneously obtaining intrinsic spectral parameters for all of these objects. In particular, we identify Markarian 501 (Mkn 501) flare data (HEGRA/1997) as essential for constraining the EBL above 30 mu m. (AU)

• Processo FAPESP: 15/15897-1 - Cherenkov Telescope Array - CTA
• Beneficiário: Luiz Vitor de Souza Filho
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 21/01473-6 - Estudo de efeitos de absorção de radiação gama no meio extragaláctico
• Beneficiário: Matheus Genaro Dantas Xavier
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 21/01089-1 - Cherenkov Telescope Array: construção e primeiras descobertas
• Beneficiário: Luiz Vitor de Souza Filho
• Modalidade de apoio: Auxílio à Pesquisa - Projetos Especiais
• Processo FAPESP: 21/00030-3 - Testes da quebra da invariância de Lorentz com astropartículas
• Beneficiário: Luiz Augusto Stuani Pereira
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado