@article{8f7d6225bd4a460b85da40eeb893100b,
title = "VVV-WIT-04: An extragalactic variable source caught by the VVV Survey",
abstract = "We report the discovery of VVV-WIT-04, a near-infrared (near-IR) variable source towards the Galactic disc located ∼0.2 arcsec apart from the position of the radio source PMN J1515−5559. The object was found serendipitously in the near-IR data of the ESO public survey VISTA Variables in the V{\'i}a L{\'a}ctea (VVV). Our analysis is based on variability, multicolour, and proper motion data from VVV and VVV eXtended surveys, complemented with archive data at longer wavelengths. We suggest that VVV-WIT-04 has an extragalactic origin as the near-IR counterpart of PMN J1515−5559. The Ks-band light curve of VVV-WIT-04 is highly variable and consistent with that of an optically violent variable quasar. The variability in the near-IR can be interpreted as the redshifted optical variability. Residuals to the proper motion vary with the magnitude suggesting contamination by a blended source. Alternative scenarios, including a transient event such as a nova or supernova, or even a binary microlensing event, are not in agreement with the available data.",
keywords = "Catalogues, Infrared: stars, Radio continuum: galaxies, Radio continuum: general, Stars: individual: VVV-WIT-04, Surveys",
author = "Saito, {R. K.} and D. Minniti and Ivanov, {V. D.} and N. Masetti and Navarro, {M. G.} and Fernandes, {R. Cid} and D. Ruschel-Dutra and Smith, {L. C.} and Lucas, {P. W.} and C. Gonzalez-Fernandez and Ramos, {R. Contreras}",
note = "Funding Information: 2004, respectively. We gratefully acknowledge the use of data from the ESO public survey programme IDs 179.B-2002 and 198.B-2004 taken with the VISTA telescope, and data products from the Cambridge Astronomical Survey Unit (CASU). This publication makes use of data products from the Wide-field Infrared Survey Explorer (WISE), which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. RKS acknowledges support from CNPq/Brazil through projects 308968/2016-6 and 421687/2016-9. PWL is supported by STFC Consolidated Grant ST/R000905/1. DRD and RCF acknowledge support from Brazilian agencies CAPES and CNPq. Support for the authors is provided by the BASAL CONICYT Center for Astrophysics and Associated Technologies (CATA) through grant AFB-170002, and the Ministry for the Economy, Development, and Tourism, Programa Iniciativa Cient{\'i}fica Milenio through grant IC120009, awarded to the Millennium Institute of Astrophysics (MAS). DM acknowledges support from FONDECYT through project Regular #1170121. Publisher Copyright: {\textcopyright} 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society",
year = "2019",
month = jan,
day = "1",
doi = "10.1093/mnras/stz2631",
language = "English",
volume = "490",
pages = "1171--1178",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
number = "1",
}