ULTI-WAVELENGTH MONITORING OF THE CHANGING-LOOK AGN NGC 2617 DURING STATE CHANGES
| Autor: | M. B. Brotherton, C. M. Gaskell, V. M. Lipunov, Konstantin Malanchev, V. L. Oknyansky, Vladimir Metlov, M. A. Burlak, N. A. Huseynov, D. A. H. Buckley, Pu Du, H. Levato, Kh. M. Mikailov, N. I. Shatsky, E. S. Gorbovskov, X. Chen, Miquel Serra-Ricart, Rafael Rebolo, A. M. Tatarnikov, Sergey S. Tsygankov, D. Kasper, R. Podesta |
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| Přispěvatelé: | Russian Foundation for Basic Research through grant 17-52- 80139 BRICS-a and by the BRICS Multilateral Joint Science and Technology Research Collaboration grant #110480. RSF grant 16-12-00085 |
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
lcsh:Astronomy
Ciencias Físicas FOS: Physical sciences Multi wavelength AGN CL AGN X-ray UV optical photometry spectroscopy purl.org/becyt/ford/1.3 [https] Astrophysics Astrophysics - Astrophysics of Galaxies Uv purl.org/becyt/ford/1 [https] Photometry Astronomía lcsh:QB1-991 Accretion disc Astrophysics of Galaxies (astro-ph.GA) X-Ray Agn CIENCIAS NATURALES Y EXACTAS Mathematics |
| Zdroj: | Odessa Astronomical Publications, Vol 30, Iss 0, Pp 117-120 (2017) Odessa Astronomical Publications; Том 30 (2017); 117-120 CONICET Digital (CONICET) Consejo Nacional de Investigaciones Científicas y Técnicas instacron:CONICET |
| ISSN: | 1810-4215 |
| Popis: | Optical and near-infrared photometry, optical spectroscopy, and soft X-ray and UV monitoring of the changing-look active galactic nucleus NGC 2617 show that it continues to have the appearance of a type-1 Seyfert galaxy. An optical light curve for 2010$-$2017 indicates that the change of type probably occurred between 2010 October and 2012 February and was not related to the brightening in 2013. In 2016 and 2017 NGC 2617 brightened again to a level of activity close to that in 2013 April. However, in 2017 from the end of the March to end of July 2017 it was in very low level and starting to change back to a Seyfert 1.8. We find variations in all passbands and in both the intensities and profiles of the broad Balmer lines. A new displaced emission peak has appeared in H$\beta$. X-ray variations are well correlated with UV$-$optical variability and possibly lead by $\sim$ 2$-$3 d. The $K$ band lags the $J$ band by about 21.5 $\pm$ 2.5 d and lags the combined $B + J$ bands by $\sim$ 25 d. $J$ lags $B$ by $\sim$ 3 d. This could be because $J$-band variability arises predominantly from the outer part of the accretion disc, while $K$-band variability is dominated by thermal re-emission by dust. We propose that spectral-type changes are a result of increasing central luminosity causing sublimation of the innermost dust in the hollow bi-conical outflow. We briefly discuss various other possible reasons that might explain the dramatic changes in NGC 2617. Comment: 4 pages, 3 figures, accepted to the OAP |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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