New changing look case in NGC 1566

Abstract

We present a study of optical, UV and X-ray light curves of the nearby changing look active galactic nucleus in the galaxy NGC 1566 obtained with the Neil Gehrels Swift Observatory and the MASTER Global Robotic Network over the period 2007 - 2018. We also report on our optical spectroscopy at the South African Astronomical Observatory with the 1.9-m telescope on the night 2018 August 2-3. A substantial increase in X-ray flux by 1.5 orders of magnitude was observed following the brightening in the UV and optical bands during the last year. After a maximum was reached at the beginning of 2018 July the fluxes in all bands decreased with some fluctuations. The amplitude of the flux variability is strongest in the X-ray band and decreases with increasing wavelength. Low-resolution spectra reveal a dramatic strengthening of the broad emission as well as high-ionization [FeX]6374 A lines. These lines were not detected so strongly in the past published spectra. The change in the type of the optical spectrum was accompanied by a significant change in the X-ray spectrum. All these facts confirm NGC 1566 to be a changing look Seyfert galaxy.

7 pages, 5 figures

References in corpus (3)

• Coronal-Line Forest AGN: the best view of the inner edge of the AGN torus?
• NGC 1566: analysis of the nuclear region from optical and near-infrared Integral Field Unit spectroscopy
• Variability of the coronal line region in NGC 4151

Cited by in corpus (20)

• A possible mechanism for multiple changing look phenomenon in Active Galactic Nuclei
• Mid-InfraRed Outburst in Nearby Galaxies (MIRONG) I: Sample Selection and Characterization
• Rapid "Turn-on" of type 1 AGN in a quiescent early type galaxy SDSS1115+0544
• BASS XXXIX: Swift-BAT AGN with changing-look optical spectra
• Reverberation Mapping of Changing-look Active Galactic Nucleus NGC 3516
• An Extreme X-ray Variability Event of a Weak-Line Quasar
• The rise and fall of the iron-strong nuclear transient PS16dtm
• The Eddington ratio-dependent changing look events in NGC 2992
• Changing-look event in NGC 3516: continuum or obscuration variability?
• A flare in the optical spotted in the changing-look Seyfert NGC 3516
• Broadband X-Ray Observations of the 2018 Outburst of the Changing-Look Active Galactic Nucleus NGC 1566
• The LSST era of supermassive black holes accretion-disk reverberation mapping
• The post-maximum behaviour of the changing-look Seyfert galaxy NGC 1566
• SDSS J075101.42+291419.1: A Super-Eddington Accreting Quasar with Extreme X-ray Variability
• Optical and X-ray discovery of the changing-look AGN IRAS23226-3843 showing extremely broad and double-peaked Balmer profiles
• Discovery of late-time X-ray flare and anomalous emission line enhancement after the nuclear optical outburst in a narrow-line Seyfert 1 Galaxy
• Dynamical evidence of the sub-parsec counter-rotating disc for a close binary of supermassive black holes in the nucleus of NGC 1068
• The Large Amplitude X-ray Variability in NGC 7589: Possible Evidence for Accretion Mode Transition
• The optically elusive, changing-look active nucleus in NGC 4156
• Thermal Comptonization in a changing corona in the changing-look active galaxy NGC 1566