In this study, we explored the possibilities to increase the performance of a neural network method previously used for the classification of uncertain blazars in Chiaro et al. (2016MNRAS.462.3180C, Cat. J/MNRAS/462/3180). We developed an optimized version of the original algorithm improving the selecting performance of about 80 per cent. The final result of this study left 15 uncertain blazar sources instead of 77 in Chiaro et al. (2016MNRAS.462.3180C, Cat. J/MNRAS/462/3180). Looking beyond γ-ray features of blazars, interesting information can be obtained from a multiwavelength study of the sources and particularly from X-ray and radio flux. In this study we tested the possibility to use those two parameters to improve the performance of the network. We did not consider any optical spectroscopy data because when considering uncertain sources, optical spectra are very often not available or not sufficiently descriptive of the nature of the source. The γ-ray flux was obtained by adding five time-integrated fluxes in five bands (0.1-0.3, 0.3-1, 1-3, 3-10, 10-100 GeV) from the 3FGL catalogue (Acero et al. 2015ApJS..218...23A, Cat. J/ApJS/218/23). Radio and X-ray data were obtained from the Fermi-LAT 4-year AGN Catalog 3LAC (Ackermann et al. 2015ApJ...810...14A, Cat. J/ApJ/810/14). Radio fluxes used were measured at frequencies of 1.4 and 0.8GHz; the X-ray fluxes were measured in the 0.1-2.4keV range. The complete list of 567 classified BCUs is presented in Table 1 in which sources are sorted by increasing likelihood of a source being a BL Lac. (1 data file).
VizieR Online Data Catalog: Classifying Fermi-LAT gamma-ray sources (Kovacevic+, 2019)
Chiaro, G.;Tosti, G.
2023
Abstract
In this study, we explored the possibilities to increase the performance of a neural network method previously used for the classification of uncertain blazars in Chiaro et al. (2016MNRAS.462.3180C, Cat. J/MNRAS/462/3180). We developed an optimized version of the original algorithm improving the selecting performance of about 80 per cent. The final result of this study left 15 uncertain blazar sources instead of 77 in Chiaro et al. (2016MNRAS.462.3180C, Cat. J/MNRAS/462/3180). Looking beyond γ-ray features of blazars, interesting information can be obtained from a multiwavelength study of the sources and particularly from X-ray and radio flux. In this study we tested the possibility to use those two parameters to improve the performance of the network. We did not consider any optical spectroscopy data because when considering uncertain sources, optical spectra are very often not available or not sufficiently descriptive of the nature of the source. The γ-ray flux was obtained by adding five time-integrated fluxes in five bands (0.1-0.3, 0.3-1, 1-3, 3-10, 10-100 GeV) from the 3FGL catalogue (Acero et al. 2015ApJS..218...23A, Cat. J/ApJS/218/23). Radio and X-ray data were obtained from the Fermi-LAT 4-year AGN Catalog 3LAC (Ackermann et al. 2015ApJ...810...14A, Cat. J/ApJ/810/14). Radio fluxes used were measured at frequencies of 1.4 and 0.8GHz; the X-ray fluxes were measured in the 0.1-2.4keV range. The complete list of 567 classified BCUs is presented in Table 1 in which sources are sorted by increasing likelihood of a source being a BL Lac. (1 data file).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
