Studies of gamma-ray absorption in the extragalactic medium

• Grant number: 21/01473-6
• Support Opportunities: Scholarships in Brazil - Master
• Start date: June 01, 2021
• End date: July 31, 2023
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Extragalactic Astrophysics
• Principal Investigator: Edivaldo Moura Santos
• Grantee: Matheus Genaro Dantas Xavier
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 15/15897-1 - Cherenkov Telescope Array - CTA, AP.TEM
• Associated scholarship(s): 22/07692-4 - Improving the precision of measurements for the highest energy gamma rays via a Bayesian formalism, BE.EP.MS

Abstract

When propagating through space, highly energetic gamma-rays can be absorbed through interactions with low energy photons from the extragalactic backgound light (EBL) leading to the production of electron-positron pairs. The absorption effect alters the spectrum of gamma-rays coming from distant astrophysical objects, it is dependent on the energy and increases with the source redshift. Therefore, the observation of active galactic nuclei (AGN) carries information on the properties of the EBL. In particular, the EBL affects predominantly the spectra of blazars in the energy range from ~10 GeV to 10 TeV. The detection of gamma-ray spectra from sources at high redshift using the new generation of air imaging Cherenkov telescopes (IACT) represented by the Cherenkov Telescope Array (CTA) will allow us to study in great detail the properties of the EBL, given that this new array of telescopes will have a better sensitivity, energy resolution and energy coverage than the current instruments. The goal of this research proposal is to reconstruct the spectra of gamma-ray extragalactic sources in the presence of absorption effects. In addition to the propagation of gamma-rays through the extragalactic medium using codes developed in the local research group, the full simulation chain of the response of the CTA telescopes should be used. (AU)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

XAVIER, Matheus Genaro Dantas. Extragalactic background light studies with gamma rays via Markov chain Monte Carlo methods. 2023. Master's Dissertation - Universidade de São Paulo (USP). Instituto de Física (IF/SBI) São Paulo.