The Detection of Fermi AGN above 100 GeV using Clustering Analysis

Abstract

The density-based clustering algorithm DBSCAN has been applied to the Fermi Large Area Telescope (LAT) dataset of $E_{\gamma }⩾100$ GeV events with $|b|>10^{\circ }$, in order to search for new very high energy (VHE) $\gamma$-ray sources. The clustering analysis returned 49 clusters, of which 21 correspond to already known VHE-emitting active galactic nuclei (AGN) within the TeVCat catalogue and a further 11 were found to be significant in a full Fermi analysis. Of these, 2 are previously detected Fermi VHE AGN, and 9 represent new VHE sources consisting of 6 BL Lac objects, one blazar of unknown type and 2 unassociated sources. Comparing these, along with the VHE AGN RBS 0679 and RBS 0970 previously detected with Fermi-LAT, to the current populations of AGN detected with ground-based instruments and Fermi suggests that the VHE-emitting AGN discovered in this study are very similar to the TeVCat AGN and therefore further observations with ground-based imaging atmospheric Cherenkov telescopes are recommended.

8 pages, 4 figures, published in MNRAS

References in corpus (6)

• The Spectrum of the Isotropic Diffuse Gamma-Ray Emission Derived From First-Year Fermi Large Area Telescope Data
• Roma-BZCAT: A multifrequency catalogue of Blazars
• A MST algorithm for source detection in gamma-ray images
• A Clustering Analysis of the Morphology of the 130 GeV Gamma-Ray Feature
• Very High Energy gamma-ray emission from RBS 0970
• Very high energy $\gamma$-ray emission from RBS 0679

Cited by in corpus (5)

• Finding counterparts for All-sky X-ray surveys with Nway: a Bayesian algorithm for cross-matching multiple catalogues
• Data mining techniques on astronomical spectra data. I : Clustering Analysis
• A MST catalogue of gamma-ray source candidates above 10 GeV and at Galactic latitudes higher than 20 degrees
• Fermi-LAT high $z$ AGN and the Extragalactic Background Light
• A blind search for intraday gamma-ray transients with Fermi-LAT: Detections of GRB and solar emissions