English

San Pedro Martir observations of microvariability in obscured quasars

Astrophysics of Galaxies 2015-06-17 v1

Abstract

Fast brightness variations are a unique tool to probe the innermost regions of active galactic nuclei (AGN). These variations are called microvariability or intra-night variability, and this phenomenon has been monitored in samples of blazars and unobscured AGNs. Detecting optical microvariations in targets hidden by the obscuring torus is a challenging task because the region responsible for the variations is hidden from our sight. However, there have been reports of fast variations in obscured Seyfert galaxies in X-rays, which rises the question whether microvariations can also be detected in obscured AGNs in the optical regime. Because the expected variations are very small and can easily be lost within the noise, the analysis requires a statistical approach. We report the use of a one-way analysis of variance, ANOVA, with which we searched for microvariability. ANOVA was successfully employed in previous studies of unobscured AGNs. As a result, we found microvariable events during three observing blocks: in two we observed the same object (Mrk 477), and in another, J0759+5050. The results on Mrk 477 confirm previous findings. However, since Mrk 477 is quite a peculiar target with hidden broad-line regions, we cannot rule out the possibility that we have serendipitously chosen a target prone to variations.

Keywords

Cite

@article{arxiv.1504.08254,
  title  = {San Pedro Martir observations of microvariability in obscured quasars},
  author = {Jana Polednikova and Alessandro Ederoclite and Jordi Cepa and José Antonio de Diego and José Ignacio González-Serrano and Angél Bongiovanni and Iván Oteo and Ana M. Pérez García and Ricardo Pérez-Martínez and Irene Pintos-Castro and Marina Ramón-Pérez and Miguel Sánchez-Portal},
  journal= {arXiv preprint arXiv:1504.08254},
  year   = {2015}
}

Comments

Research note, 5 pages, 2 figures, accepted for publication in Astronomy and Astrophysics