Details

Autor(en) / Beteiligte

• Chiaro, G.
• Salvetti, D.
• La Mura, G.
• Giroletti, M.
• Thompson, D. J.
• Bastieri, D.

Titel

Blazar flaring patterns (B-FlaP) classifying blazar candidate of uncertain type in the third Fermi-LAT catalogue by artificial neural networks

Ist Teil von

• Monthly notices of the Royal Astronomical Society, 2016-11, Vol.462 (3), p.3180-3195

Ort / Verlag

London: Oxford University Press

Erscheinungsjahr

2016

Quelle

EZB-FREE-00999 freely available EZB journals

Beschreibungen/Notizen

• The Fermi-Large Area Telescope (LAT) is currently the most important facility for investigating the GeV γ-ray sky. With Fermi-LAT, more than three thousand γ-ray sources have been discovered so far. 1144 (∼40 per cent) of the sources are active galaxies of the blazar class, and 573 (∼20 per cent) are listed as blazar candidate of uncertain type (BCU), or sources without a conclusive classification. We use the empirical cumulative distribution functions and the artificial neural networks for a fast method of screening and classification for BCUs based on data collected at γ-ray energies only, when rigorous multiwavelength analysis is not available. Based on our method, we classify 342 BCUs as BL Lacs and 154 as flat-spectrum radio quasars, while 77 objects remain uncertain. Moreover, radio analysis and direct observations in ground-based optical observatories are used as counterparts to the statistical classifications to validate the method. This approach is of interest because of the increasing number of unclassified sources in Fermi catalogues and because blazars and in particular their subclass high synchrotron peak objects are the main targets of atmospheric Cherenkov telescopes.