Potential of the next generation VHE instruments to probe the EBL (I): the low- and mid-VHE

TL;DR

This paper explores how upcoming very-high energy gamma-ray observatories can improve constraints on the extragalactic background light by analyzing the attenuation of gamma-rays from distant sources, building on current observational techniques.

Contribution

It assesses the potential of next-generation VHE instruments to enhance EBL density measurements by extrapolating current results and exploring new methods.

Findings

Future VHE observatories can significantly improve EBL constraints.

Extrapolated current data suggests better sensitivity to EBL features.

New methods may enable more precise measurements of the EBL density.

Abstract

The diffuse meta-galactic radiation field at ultraviolet to infrared wavelengths - commonly labeled extragalactic background light (EBL) - contains the integrated emission history of the universe. Difficult to access via direct observations indirect constraints on its density can be derived through observations of very-high energy (VHE; E>100 GeV) gamma-rays from distant sources: the VHE photons are attenuated via pair-production with the low energy photons from the EBL, leaving a distinct imprint in the VHE spectra measured on earth. Discoveries made with current generation VHE observatories like H.E.S.S. and MAGIC enabled strong constraints on the density of the EBL especially in the near-infrared. In this article the prospect of future VHE observatories to derive new constraints on the EBL density are discussed. To this end, results from current generation instruments will be extrapolated to the future experiment's sensitivity and investigated for their power to enable new methods and improved constraints on the EBL density.