SPECTRAL OPTICAL MONITORING OF THE NARROW-LINE SEYFERT 1 GALAXY Ark 564

Journal Article · Sat Sep 15 04:00:00 EDT 2012 · Astrophysical Journal, Supplement Series

DOI:https://doi.org/10.1088/0067-0049/202/1/10· OSTI ID:22089872

Shapovalova, A. I.; Burenkov, A. N. ^[1]; Popovic, L. C.; Kovacevic, J. ^[2]; Chavushyan, V. H.; Valdes, J. R.; Torrealba, J.; Carrasco, L. ^[3]; Ilic, D.; Kovacevic, A. ^[4]; Kollatschny, W. ^[5]; Bochkarev, N. G. ^[6]; Leon-Tavares, J. ^[7]; Mercado, A. ^[8]; Benitez, E.; Dultzin, D. ^[9]

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1. Special Astrophysical Observatory of the Russian AS, Nizhnij Arkhyz, Karachaevo-Cherkesia 369167 (Russian Federation)
2. Astronomical Observatory, Volgina 7, 11160 Belgrade 74 (Serbia)
3. Instituto Nacional de Astrofisica, Optica y Electronica, Apartado Postal 51-216, 72000 Puebla (Mexico)
4. Isaac Newton Institute of Chile, Yugoslavia Branch, Belgrade (Serbia)
5. Institut fuer Astrophysik, Georg-August-Universitaet, Goettingen (Germany)
6. Sternberg Astronomical Institute, Moscow (Russian Federation)
7. Aalto University Metsaehovi Radio Observatory, Metsaehovintie 114, FIN-02540 Kylmaelae (Finland)
8. Universidad Politecnica de Baja California, Av. de la Industria 291, 21010 Mexicali, B.C. (Mexico)
9. Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-264, Mexico, D.F. 04510 (Mexico)

We present the results of a long-term (1999-2010) spectral optical monitoring campaign of the active galactic nucleus (AGN) Ark 564, which shows a strong Fe II line emission in the optical. This AGN is a narrow-line Seyfert 1 (NLS1) galaxy, a group of AGNs with specific spectral characteristics. We analyze the light curves of the permitted H{alpha}, H{beta}, optical Fe II line fluxes, and the continuum flux in order to search for a time lag between them. Additionally, in order to estimate the contribution of iron lines from different multiplets, we fit the H{beta} and Fe II lines with a sum of Gaussian components. We find that during the monitoring period the spectral variation (F{sub max}/F{sub min}) of Ark 564 is between 1.5 for H{alpha} and 1.8 for the Fe II lines. The correlation between the Fe II and H{beta} flux variations is of higher significance than that of H{alpha} and H{beta} (whose correlation is almost absent). The permitted-line profiles are Lorentzian-like and do not change shape during the monitoring period. We investigate, in detail, the optical Fe II emission and find different degrees of correlation between the Fe II emission arising from different spectral multiplets and the continuum flux. The relatively weak and different degrees of correlations between permitted lines and continuum fluxes indicate a rather complex source of ionization of the broad-line emission region.

• OSTI ID: 22089872
• Journal Information: Astrophysical Journal, Supplement Series, Journal Name: Astrophysical Journal, Supplement Series Journal Issue: 1 Vol. 202; ISSN 0067-0049; ISSN APJSA2
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTROPHYSICS
CORRELATIONS
GALAXY NUCLEI
ION EMISSION
IONIZATION
IRON IONS
MONITORING
MULTIPLETS
QUASARS
SEYFERT GALAXIES
VARIATIONS
VISIBLE RADIATION