English

AGN candidates in the VVV near-IR galaxy catalogue

Astrophysics of Galaxies 2023-02-22 v1

Abstract

The goal of this work is to search for Active Galactic Nuclei (AGN) in the Galactic disc at very low latitudes with |b| << 2^\circ. For this, we studied the five sources from the VVV near-infrared galaxy catalogue that have also WISE counterparts and present variability in the VIrac VAriable Classification Ensemble (VIVACE) catalogue. In the near-infrared colour-colour diagrams, these objects have in general redder colours compared to the rest of the sources in the field. In the mid-infrared ones, they are located in the AGN region, however there is a source that presents the highest interstellar extinction and different mid-IR colours to be a young stellar object (YSO). We also studied the source variability using two different statistical methods. The fractional variability amplitude σrms\sigma_{rms} ranges from 12.6 to 33.8, being in concordance with previous results found for type-1 AGNs. The slopes of the light curves are in the range (2.6-4.7) ×104\times 10^{-4} mag/day, also in agreement with results reported on quasars variability. The combination of all these results suggest that four galaxies are type-1 AGN candidates whereas the fifth source likely a YSO candidate.

Keywords

Cite

@article{arxiv.2302.05595,
  title  = {AGN candidates in the VVV near-IR galaxy catalogue},
  author = {Laura D. Baravalle and Eduardo O. Schmidt and M. Victoria Alonso and Ana Pichel and Dante Minniti and Adriana R. Rodríguez-Kamenetzky and Nicola Masetti and Carolina Villalon and Leigh C. Smith and Philip W. Lucas},
  journal= {arXiv preprint arXiv:2302.05595},
  year   = {2023}
}

Comments

11 pages, 6 figures, 5 tables. Accepted for publication in Monthly Notices of the Royal Astronomical Society (MNRAS)