A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
New changing look case in NGC 1566
Tekijät: Oknyansky VL, Winkler H, Tsygankov SS, Lipunov VM, Gorbovskoy ES, van Wyk F, Buckley DAH, Tyurina NV
Kustantaja: OXFORD UNIV PRESS
Julkaisuvuosi: 2019
Journal: Monthly Notices of the Royal Astronomical Society
Tietokannassa oleva lehden nimi: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
Lehden akronyymi: MON NOT R ASTRON SOC
Vuosikerta: 483
Numero: 1
Aloitussivu: 558
Lopetussivu: 564
Sivujen määrä: 7
ISSN: 0035-8711
eISSN: 1365-2966
DOI: https://doi.org/10.1093/mnras/sty3133
Rinnakkaistallenteen osoite: https://research.utu.fi/converis/portal/detail/Publication/40018364
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 [Fe X] 6374 angstrom 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.
Ladattava julkaisu This is an electronic reprint of the original article. |  |
