EBL Constraints Using a Sample of TeV Gamma-Ray Emitters Measured with the MAGIC Telescopes

TL;DR

This paper uses gamma-ray spectra from MAGIC telescopes observing blazars across various redshifts to constrain the extragalactic background light density and its evolution, providing insights into cosmic light history.

Contribution

It presents a combined likelihood analysis of multiple blazar observations to improve constraints on the EBL, extending previous single-source studies.

Findings

Strong limits on EBL density from multiple blazars

Probing EBL evolution across different wavelengths

Implications for EBL models and future MAGIC observations

Abstract

MAGIC is a stereoscopic system of two Imaging Atmospheric Cherenkov Telescopes operating in the very high energy (VHE) range from about 50 GeV to over 50 TeV. The VHE gamma-ray spectra measured at Earth carry an imprint of the extragalactic background light (EBL) and can be used to study the EBL density and its evolution in time. In the last few years, precision measurements of several blazars in the redshift range from z=0.03 up to z=0.9 were performed with MAGIC obtaining strong limits on the EBL density from single sources. In this paper, we present the results from a combined likelihood analysis using this broad redshift range sample of blazars allowing us to probe the EBL at different wavelengths. The implications on the EBL models and perspectives for future observations with MAGIC are also discussed.