Searching for Extragalactic Sources in the VISTA Variables in the Vía Láctea Survey

Abstract

We search for extragalactic sources in the VISTA Variables in the Vía Láctea survey that are hidden by the Galaxy. Herein, we describe our photometric procedure to find and characterize extragalactic objects using a combination of SExtractor and PSFEx. It was applied in two tiles of the survey: d010 and d115, without previous extragalactic IR detections, in order to obtain photometric parameters of the detected sources. The adopted criteria to define extragalactic candidates include CLASS_STAR < 0.3; 1.0 < R1/2 < 5.0 arcsec; 2.1 < C < 5; and Phi > 0.002 and the colors: 0.5 < (J - K_s) < 2.0 mag; 0.0 < (J - H) < 1.0 mag; 0.0 < (H - K_s) < 2.0 mag and (J - H) + 0.9 (H - K_s) > 0.44 mag. We detected 345 and 185 extragalactic candidates in the d010 and d115 tiles, respectively. All of them were visually inspected and confirmed to be galaxies. In general, they are small and more circular objects, due to the near-IR sensitivity to select more compact objects with higher surface brightness. The procedure will be used to identify extragalactic objects in other tiles of the VVV disk, which will allow us to study the distribution of galaxies and filaments hidden by the Milky Way.

25 pages, 2 tables, 15 figures. Accepted for publication in The Astronomical Journal

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Cited by in corpus (7)

• The VVV Near-IR Galaxy Catalogue beyond the Galactic disk
• The First Galaxy Cluster Discovered by the VISTA Variables in the Vía Láctea Survey
• Overdensity of VVV galaxies behind the Galactic bulge
• Dust extinction map of the Galactic plane based on the VVV survey data
• Searching for globular clusters in the inner halo of the Circinus galaxy
• AGN candidates in the VVV near-IR galaxy catalogue
• Galaxy clustering in the VVV Near-IR Galaxy Catalogue