High energy gamma-ray sources in the VVV survey - I. The Blazars

ANA CAROLINA PICHEL ; M. VICTORIA ALONSO; DANTE MINNITI; GEORGINA COLDWELL; LAURA DONOSO; ADRIAN ROVERO; JUAN CABRAL; NICOLA MASETTI; LAURA BARAVALLE; JUAN CARLOS BEAMIN; BRUNO SANCHEZ

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2020 vol. 491 p. 3448 - 3460

0035-8711

There is a lack of blazar detections in the galactic plane area, even in the most recent blazar catalogues, mainly due to incompleteness resulting from interstellar dust and stellar contamination of our Galaxy. The VISTA variables in the Vía Láctea survey (VVV) aims to map variable sources towards the galactic plane in the near-infrared. There are three catalogued and one candidate blazars in the VVV area, that are also detected by Fermi-LAT in the gamma ray band, and by the Wide-field Infrared Survey Explorer (WISE) at mid-infrared wavelengths.We study the physical properties of these blazars in order to use them as a reference that would allow us to find counterparts of other unidentified gamma-ray sources in the future. All four sources have VVV counterparts, and two of them, 5BZUJ1731-3003 and 5BZQJ1802-3940are also associated with WISE sources. They present very different properties compared with stellar or extragalactic objects. Their VVV K s light curves show significant variability, and are characterised using a machine learning analysis. In particular, the blazar 5BZQJ1802-3940, aflat spectrum radio quasar, exhibits the smallest uncertainties in the Fermi-LAT position and it is a bright WISE source. Its near-infrared properties in the Colour-Magnitude and Colour-Colour Diagrams are very different from the stars and extragalactic objects in the field. It hasthe highest amplitude in the K s differential light curve and fractional variability amplitude. The present pilot study will allow us to search for and identify other blazars hidden behind the Galactic plane using the VVV survey database.