Discovery of new changing look in NGC 1566. Issue Volume 15:Issue S356(2019) (October 2019)

• Record Type: Journal Article
• Authors: Oknyansky, Victor L.; Tsygankov, Sergey S.; Lipunov, Vladimir M.; Gorbovskoy, Evgeny S.; Tyurina, Nataly V.
• Editors: Pović, Mirjana; Marziani, Paola; Masegosa, Josefa; Netzer, Hagai; Negu, Seblu H.; Tessema, Solomon B.
• Is Part Of: Proceedings of the International Astronomical Union. Volume 15:Issue S356(2019)
• Page Start: 127
• Page End: 131
• Publication Date: 2019-10
• Subjects: AGN, -- Spectra, -- photometry, -- X-ray, -- variability, -- NGC 1566; Astronomy -- Congresses; Astronomy -- Periodicals; 520
• DOI: 10.1017/S1743921320002720
• Languages: English
• ISSNs: 1743-9213

Abstract

Abstract: We present continuation of the multi-wavelength (from X-ray to optical) monitoring of the nearby changing look (CL) active galactic nucleus in the galaxy NGC 1566 performed with the Neil Gehrels Swift Observatory, the MASTER Global Robotic Network over the period 2007–2019. We also present continuation of optical spectroscopy using the South African Astronomical Observatory 1.9-m telescope between Aug. 2018 and Mar. 2019. We investigate remarkable re-brightenings in of the light curve following the decline from the bright phase observed at Dec. 2018 and at the end of May 2019. For the last optical spectra (31 Nov. 2018–28 Mar. 2019) we see dramatic changes compared to 2 Aug. 2018, accompanied by the fading of broad emission lines and high-ionization [FeX]6374Å line. Effectively, one more CL was observed for this object: changing from Sy1.2 to the low state as Sy 1.8–Sy1.9 type. Some possible explanations of the observed CL are discussed.