A new strategy to select candidate blazars for VHE observation

TL;DR

This paper introduces a comprehensive method for selecting candidate blazars for very-high-energy (VHE) observations by extrapolating GeV spectra from Fermi data, correcting for EBL absorption, and ranking by flux.

Contribution

It presents a novel, complete all-sky selection strategy for VHE blazars based on Fermi-LAT data and spectral extrapolation, improving candidate identification accuracy.

Findings

The method successfully identifies promising VHE blazar candidates.

Cross-validation with known VHE blazars supports its effectiveness.

The strategy enhances the efficiency of VHE observation campaigns.

Abstract

A new strategy to select candidate blazars for VHE observations, that gives an inherently complete sample from an all-sky compilation (excluding a narrow region around the galactic plane) of GeV-bright blazars is presented. The strategy is based on selecting candidate VHE blazars from a GeV-detected blazar sample, namely the LAT-bright-AGN-sample (LBAS) of the Fermi Gamma-ray Space Telescope (FGST). The intrinsic spectra in the VHE regime is estimated based on the extrapolation of the GeV spectra measured with FGST. This is corrected for the unavoidable extinction due to the Extragalactic Background Light (EBL) in the UV to mid-IR. The resulting observable spectra ranked by the integrated flux is used to extract candidates for observations in the VHE regime with Imaging Atmospheric Cherenkov Telescopes (IACTs). The predictions are cross-checked using the sample of known VHE blazars.