E. Bon

Contribution of a disc component to single-peaked broad lines of active galactic nuclei

We study the disc emission component hidden in the single-peaked broad emission lines (BELs) of active galactic nuclei. We compare the observed broad lines from a sample of 90 Seyfert 1 spectra taken from the Sloan Digital Sky Survey with simulated line profiles. We consider a two-component broad line region model where an accretion disc and a surrounding non-disc region with isotropic cloud velocities generate the simulated BEL profiles. The analysis is mainly based on the measurements of the full widths (at 10 per cent, 20 per cent and 30 per cent of the maximum intensity) and on the asymmetries of the line profiles. Comparing these parameters for the simulated and observed Hα broad lines, we found that the hidden disc emission may be present in BELs even if the characteristic of two-peaked-line profiles is absent. For the available sample of objects (Seyfert 1 galaxies with single-peaked BELs), our study indicates that, in the case of the hidden disc emission in single-peaked broad-line profiles, the disc inclination tends to be small (mostly i < 25°) and that the contribution of the disc emission to the total flux should be smaller than the contribution of the surrounding region.

Evidence for periodicity in 43-year-long monitoring of NGC 5548

We present an analysis of 43 years (1972 to 2015) of spectroscopic observations of the Seyfert 1 galaxy NGC 5548. This includes 12 years of new unpublished observations (2003 to 2015). We compiled about 1600 H

Complex Broad Emission Line Profiles of AGN - Geometry of the Broad Line Region

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Complex emission line region of Mrk 817

spectra and analyzed the long-term spectral variations of the 5100 A\ continuum and the H

The disk emission in the Broad Line Region of Active Galactic Nuclei

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Determination of Accretion Disc Parameters in the Case of Five AGN with Double‐peaked Lines

line. Our analysis is based on standard procedures including the Lomb-Scargle method, which is known to be rather limited to such heterogeneous data sets, and new method developed specifically for this project that is more robust and reveals a

Astronomy and catastrophes through myth and old texts.

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Activities of the Group for Astrophysical Spectroscopy 2005-2008

5700 day periodicity in the continuum light curve, the H

The flux ratio of [OIII]lambda lambda4959,5007 lines in Sy2: Comparison with theoretical calculations

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The emission line shapes of the Seyfert 1 galaxy Mrk 817

light curve and the radial velocity curve of the red wing of the H