Identifying TeV Source Candidates among Fermi-LAT Unclassified Blazars

Abstract

Blazars and in particular the subclass of high synchrotron peaked Active Galactic Nuclei are among the main targets for the present generation of Imaging Atmospheric Cherenkov Telescopes (IACTs) and will remain of great importance for very high-energy $\gamma$-ray science in the era of the Cherenkov Telescope Array (CTA). Observations by IACTs, which have relatively small fields of view ($\sim$ few degrees), are limited by viewing conditions; therefore, it is important to select the most promising targets in order to increase the number of detections. The aim of this paper is to search for unclassified blazars among known $\gamma$-ray sources from the Fermi Large Area Telescope (LAT) third source catalog that are likely detectable with IACTs or CTA. We use an artificial neural network algorithm and updated analysis of Fermi-LAT data. We found 80 $\gamma$-ray source candidates, and for the highest-confidence candidates, we calculate their potential detectability with IACTs and CTA based on an extrapolation of their energy spectra. Follow-up observations of our source candidates could significantly increase the current TeV source population sample and could ultimately confirm the efficiency of our algorithm to select TeV sources.

arXiv comment11 pages, 3 figures, accepted for publication in ApJ

References in corpus (19)

• The Large Area Telescope on the Fermi Gamma-ray Space Telescope Mission
• The Spectral Energy Distribution of Fermi bright blazars
• The Cosmic Infrared Background: Measurements and Implications
• Extragalactic Background Light Inferred from AEGIS Galaxy SED-type Fractions
• The major upgrade of the MAGIC telescopes, Part II: A performance study using observations of the Crab Nebula
• Development of the Model of Galactic Interstellar Emission for Standard Point-Source Analysis of Fermi Large Area Telescope Data
• 3FHL: The Third Catalog of Hard Fermi-LAT Sources
• A high performance likelihood reconstruction of gamma-rays for Imaging Atmospheric Cherenkov Telescopes
• The Extragalactic Background Light and the Gamma-ray Opacity of the Universe
• Cosmic Infrared Background and Early Galaxy Evolution
• Characterizing the Gamma-Ray Variability of the Brightest Flat Spectrum Radio Quasars Observed with the Fermi LAT
• Classification and Ranking of Fermi LAT Gamma-ray Sources from the 3FGL Catalog using Machine Learning Techniques
• 2WHSP: A catalog of HE and VHE gamma-ray blazars and blazar candidates
• Monte Carlo studies for the optimisation of the Cherenkov Telescope Array layout
• The Extragalactic Gamma-ray Sky in the Fermi era
• The discovery of high power - high synchrotron peak blazars
• Blazar Flaring Patterns (B-FlaP): Classifying Blazar Candidates of Uncertain type in the third Fermi-LAT catalog by Artificial Neural Networks
• Research and characterisation of blazar candidates among the Fermi/LAT 3FGL catalogue using multivariate classifications
• 3FGLzoo. Classifying 3FGL Unassociated Fermi-LAT Gamma-ray Sources by Artificial Neural Networks

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• Searching for TeV Candidates in 4LAC High-synchrotron-peaked Frequency BL Lac Objects
• A New Multi-Wavelength Census of Blazars
• Exploring TeV candidates of Fermi blazars through machine learning
• Identifying the 3FHL Catalog. IV. Swift Observations of Unassociated Fermi-LAT 3FHL Sources
• An empirical "high-confidence" candidate zone for $Fermi$ BL Lacertae objects