BL Lac candidates for TeV observations

TL;DR

This paper develops new IR and X-ray based criteria to identify potential TeV-emitting BL Lac objects, expanding the list of candidates for ground-based Cherenkov telescope observations.

Contribution

The study introduces novel selection criteria for TeV BL Lac candidates using IR and X-ray data, increasing the pool of potential targets beyond known sources.

Findings

Identified 41 potential TeV BL Lac candidates from ROMA-BZCAT.

Discovered 54 additional candidates from extended IR and X-ray surveys.

Tentatively classified 16 unidentified X-ray sources as BL Lac candidates.

Abstract

BL Lac objects are the most numerous class of extragalactic TeV-detected sources. One of the biggest difficulties in investigating their TeV emission resides in their limited number, since only 47 BL Lacs are known as TeV emitters. In this paper, we propose new criteria to select TeV BL Lac candidates based on the infrared (IR) and X-ray observations. We apply our selection criteria to the BL Lac objects listed in the ROMA-BZCAT catalog so identifying 41 potential TeV emitters. We then consider a search over a more extended sample combining the ROSAT bright source catalog and the WISE all-sky survey revealing 54 additional candidates for TeV observations. Our investigation also led to a tentative classification of 16 unidentified X-ray sources as BL Lac candidates. This analysis provides new interesting BL Lac targets for future observations with ground based Cherenkov telescopes.