Browsing by Author "Paggi, Alessandro"

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    Optical characterization of WISE selected blazar candidates
    (2019) de Menezes, Raniere; Pena-Herazo, Harold A.; Marchesini, Ezequiel J.; D'Abrusco, Raffaele; Masetti, Nicola; Nemmen, Rodrigo; Massaro, Francesco; Ricci, Federica; Landoni, Marco; Paggi, Alessandro; Smith, Howard A.
    Context. Over the last decade more than five thousand gamma-ray sources have been detected by the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope. Given the positional uncertainty of the telescope, nearly 30% of these sources remain without an obvious counterpart at lower energies. This has motivated the release of new catalogs of gamma-ray counterpart candidates and several follow up campaigns in the last decade.
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    Two New Catalogs of Blazar Candidates in the WISE Infrared Sky
    (2019) D'Abrusco, Raffaele; Alvarez Crespo, Nuria; Massaro, Francesco; Campana, Riccardo; Chavushyan, Vahram; Landoni, Marco; La Franca, Fabio; Masetti, Nicola; Milisavljevic, Dan; Paggi, Alessandro; Ricci, Federica; Smith, Howard A.
    We present two catalogs of radio-loud candidate blazars whose Wide-Field Infrared Survey Explorer (WISE) mid-infrared colors are selected to be consistent with the colors of confirmed gamma-ray-emitting blazars. The first catalog is the improved and expanded release of the WISE Blazar-like Radio-Loud Sources (WIBRaLS) catalog presented by D'Abrusco et al. It includes sources detected in all four WISE filters, spatially cross-matched with radio sources in one of three radio surveys and radio-loud based on their q(22) spectral parameter. WIBRaLS2 includes 9541 sources classified as BL Lacs, flat-spectrum radio quasars, or mixed candidates based on their WISE colors. The second catalog, called KDEBLLACS, based on a new selection technique, contains 5579 candidate BL Lacs extracted from the population of WISE sources detected in the first three WISE passbands ([3.4], [4.6], and [12]) only, whose mid-infrared colors are similar to those of confirmed, gamma-ray BL Lacs. Members of KDBLLACS are also required to have a radio counterpart and be radio-loud based on the parameter q(12), defined similarly to the q(22) used for the WIBRaLS2. We describe the properties of these catalogs and compare them with the largest samples of confirmed and candidate blazars in the literature. We cross-match the two new catalogs with the most recent catalogs of gamma-ray sources detected by the Fermi Large Area Telescope. Since spectroscopic observations of candidate blazars from the first WIBRaLS catalog within the uncertainty regions of gamma-ray unassociated sources confirmed that similar to 90% of these candidates are blazars, we anticipate that these new catalogs will again play an important role in the identification of the gamma-ray sky.