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Browsing by Author "La Franca, F."

Browsing by Author "La Franca, F."

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  • The gamma-ray blazar quest: new optical spectra, state of art and future perspectives 
    Massaro, Francesco; Álvarez Crespo, N.; D'Abrusco, Raffaele; Landoni, M.; Masetti, N.; Ricci, F.; Milisavljevic, D.; Paggi, A.; Chavushyan, V.; Jiménez-Bailón, E.; Patiño-Álvarez, V.; Strader, J.; Chomiuk, L.; La Franca, F.; Smith, Howard A.; Tosti, G. (2016)
    We recently developed a procedure to recognize ?-ray blazar candidates within the positional uncertainty regions of the unidentified/unassociated ?-ray sources (UGSs). Such procedure was based on the discovery that Fermi ...
  • HYPerluminous quasars at the Epoch of ReionizatION (HYPERION): A new regime for the X-ray nuclear properties of the first quasars 
    Zappacosta, L.; Piconcelli, E.; Fiore, F.; Saccheo, I.; Valiante, R.; Vignali, C.; Vito, F.; Volonteri, M.; Bischetti, M.; Comastri, A.; Done, C.; Elvis, M.; Giallongo, E.; La Franca, F.; Lanzuisi, G.; Laurenti, M.; Miniutti, G.; Bongiorno, A.; Brusa, M.; Civano, F.; Carniani, S.; D'Odorico, V.; Feruglio, C.; Gallerani, S.; Gilli, R.; Grazian, A.; Guainazzi, M.; Marinucci, A.; Menci, N.; Middei, R.; Nicastro, F.; Puccetti, S.; Tombesi, F.; Tortosa, A.; Testa, V.; Vietri, G.; Cristiani, S.; Haardt, F.; Maiolino, R.; Schneider, R.; Tripodi, R.; Vallini, L.; Vanzella, E. (2023)
    The existence of luminous quasars (QSOs) at the epoch of reionization (EoR; i.e., z > 6) powered by well-grown supermassive black holes (SMBHs) with masses ?10<sup>9</sup> M<sub>?</sub> challenges models of early SMBH ...
  • Optical archival spectra of blazar candidates of uncertain type in the 3rd Fermi Large Area Telescope Catalog 
    Álvarez Crespo, N.; Massaro, Francesco; D'Abrusco, Raffaele; Landoni, M.; Masetti, N.; Chavushyan, V.; Jiménez-Bailón, E.; La Franca, F.; Milisavljevic, D.; Paggi, A.; Patiño-Álvarez, V.; Ricci, F.; Smith, Howard A. (2016)
    Despite the fact that blazars constitute the rarest class among active galactic nuclei (AGNs) they are the largest known population of associated ?-ray sources. Many of the ?-ray objects listed in the Fermi-Large Area ...
  • Optical spectroscopic observations of gamma-ray blazar candidates VIII: the 2016-2017 follow up campaign carried out at SPM, NOT, KPNO and SOAR telescopes 
    Marchesini, E. J.; Peña-Herazo, H. A.; Álvarez Crespo, N.; Ricci, Federica; Negro, M.; Milisavljevic, D.; Massaro, F.; Masetti, N.; Landoni, M.; Chavushyan, V.; D'Abrusco, Raffaele; Jiménez-Bailón, E.; La Franca, F.; Paggi, A.; Smith, Howard A.; Tosti, G. (2019)
    The third Fermi source catalog lists 3033 ? -ray sources above 4s significance. More than 30% are classified as either unidentified/unassociated Gamma-ray sources (UGSs), with about 20% classified as Blazar candidates of ...
  • Optical spectroscopic observations of gamma-ray blazar candidates. IX. Optical archival spectra and further observations from SOAR and OAGH 
    Peña-Herazo, H. A.; Massaro, F.; Chavushyan, V.; Marchesini, E. J.; Paggi, A.; Landoni, M.; Masetti, N.; Ricci, F.; D'Abrusco, Raffaele; Milisavljevic, D.; Jiménez-Bailón, E.; La Franca, F.; Smith, Howard A.; Tosti, G. (2019)
    Nearly one third of the sources in the Fermi-LAT catalogs lacks a lower energy counterpart, hence being referred as unidentified/unassociated gamma-ray sources (UGSs). In order to firmly classify them, dedicated multifrequency ...
  • Optical Spectroscopic Observations of Gamma-ray Blazar Candidates. V. TNG, KPNO, and OAN Observations of Blazar Candidates of Uncertain Type in the Northern Hemisphere 
    Álvarez Crespo, N.; Masetti, N.; Ricci, F.; Landoni, M.; Patiño-Álvarez, V.; Massaro, Francesco; D'Abrusco, R.; Paggi, A.; Chavushyan, V.; Jiménez-Bailón, E.; Torrealba, J.; Latronico, L.; La Franca, F.; Smith, Howard A.; Tosti, G. (2016)
    The extragalactic ?-ray sky is dominated by emission from blazars, a peculiar class of active galactic nuclei. Many of the ?-ray sources included in the Fermi-Large Area Telescope Third Source catalog (3FGL) are classified ...
  • Optical Spectroscopic Observations of Gamma-Ray Blazar Candidates. VI. Further Observations from TNG, WHT, OAN, SOAR, and Magellan Telescopes 
    Álvarez Crespo, N.; Massaro, Francesco; Milisavljevic, D.; Landoni, M.; Chavushyan, V.; Patiño-Álvarez, V.; Masetti, N.; Jiménez-Bailón, E.; Strader, J.; Chomiuk, L.; Katagiri, H.; Kagaya, M.; Cheung, C. C.; Paggi, A.; D'Abrusco, Raffaele; Ricci, F.; La Franca, F.; Smith, Howard A.; Tosti, G. (2016)
    Blazars, one of the most extreme classes of active galaxies, constitute so far the largest known population of ?-ray sources, and their number is continuously growing in the Fermi catalogs. However, in the latest release ...
  • Optical spectroscopic observations of gamma-ray blazar candidates. VII. Follow-up campaign in the southern hemisphere 
    Peña-Herazo, H. A.; Marchesini, E. J.; Álvarez Crespo, N.; Ricci, F.; Massaro, F.; Chavushyan, V.; Landoni, M.; Strader, J.; Chomiuk, L.; Cheung, C. C.; Masetti, N.; Jiménez-Bailón, E.; D'Abrusco, R.; Paggi, A.; Milisavljevic, D.; La Franca, F.; Smith, H. A.; Tosti, G. (2017)
    Searching for low energy counterparts of ? -rays sources is one of the major challenges in modern ? -ray astronomy. In the third Fermi source catalog about 30% of detected sources are unidentified/unassociated Gamma-ray ...
  • Optical spectroscopic observations of gamma-ray blazar candidates. X. Results from the 2018-2019 SOAR and OAN-SPM observations of blazar candidates of uncertain type 
    de Menezes, R.; Amaya-Almazán, R. A.; Marchesini, E. J.; Peña-Herazo, H. A.; Massaro, F.; Chavushyan, V.; Paggi, A.; Landoni, M.; Masetti, N.; Ricci, F.; D'Abrusco, Raffaele; La Franca, F.; Smith, Howard A.; Milisavljevic, D.; Tosti, G.; Jiménez-Bailón, E.; Cheung, C. C. (2020)
    The fourth Fermi Large Area Telescope Source Catalog (4FGL) lists over 5000 ? -ray sources with statistical significance above 4 s . About 23% of the sources listed in this catalog are unidentified/unassociated ? -ray ...
  • Optical spectroscopic observations of low-energy counterparts of Fermi-LAT ?-ray sources 
    Peña-Herazo, H. A.; Amaya-Almazán, R. A.; Massaro, F.; de Menezes, R.; Marchesini, E. J.; Chavushyan, V.; Paggi, A.; Landoni, M.; Masetti, N.; Ricci, F.; D'Abrusco, Raffaele; Cheung, C. C.; La Franca, F.; Smith, H. A.; Milisavljevic, D.; Jiménez-Bailón, E.; Patiño-Álvarez, V. M.; Tosti, G. (2020)
    Context. A significant fraction of all ?-ray sources detected by the Large Area Telescope aboard the Fermi satellite is still lacking a low-energy counterpart. In addition, there is still a large population of ?-ray sources ...

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