| Full text | |
| Author(s): |
Genaro, M.
;
Pereira, L. A. Stuani
;
Pimentel, D. R. de Matos
;
Santos, E. Moura
Total Authors: 4
|
| Document type: | Journal article |
| Source: | Journal of Cosmology and Astroparticle Physics; v. N/A, n. 3, p. 45-pg., 2024-03-01. |
| Abstract | |
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) | |
| FAPESP's process: | 15/15897-1 - Cherenkov Telescope Array - CTA |
| Grantee: | Luiz Vitor de Souza Filho |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 21/01473-6 - Studies of gamma-ray absorption in the extragalactic medium |
| Grantee: | Matheus Genaro Dantas Xavier |
| Support Opportunities: | Scholarships in Brazil - Master |
| FAPESP's process: | 21/01089-1 - Cherenkov Telescope Array: construction and first discoveries |
| Grantee: | Luiz Vitor de Souza Filho |
| Support Opportunities: | Special Projects |
| FAPESP's process: | 21/00030-3 - Tests of Lorentz Invariance Violation with Astroparticles |
| Grantee: | Luiz Augusto Stuani Pereira |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |