Volume 522, November 2010
|Number of page(s)||13|
|Published online||28 October 2010|
Line profile and continuum variability in the very broad-line Seyfert galaxy Mrk 926*
Institut für Astrophysik, Universität Göttingen,
Friedrich-Hund Platz 1,
Accepted: 8 June 2010
Aims. We present results of an intensive spectroscopic variability campaign of the very broad-line Seyfert 1 galaxy Mrk 926. Our aim is to investigate the broad-line region (BLR) by studying the intensity and line profile variations of this galaxy on short timescales.
Methods. High signal-to-noise ratio (S/N) spectra were taken with the 9.2 m Hobby-Eberly Telescope (HET) in identical conditions during two observing campaigns in 2004 and 2005. After the spectral reduction and internal calibration we achieved a relative flux accuracy of better than 1%.
Results. The rms profiles of the very broad Balmer lines have shapes that differ from their mean line profiles, consisting of two inner (v ≲ ± 6000 km s-1) and two outer (v ≳ ± 6000 km s-1) line components in addition to a central component (v ≲ ± 600 km s-1). These outer and inner line segments varied with different amplitudes during our campaign. The radius of the BLR is very small with an upper limit of 2 light-days for the Hβ BLR size. We derived an upper limit to the central black hole mass of M = 11.2 × 107M⊙. The 2-D cross-correlation functions CCF(τ, v) of Hβ and Hα are flat within the error limits. The response of the Balmer line segments with respect to continuum variations is different in the outer and inner wings of Hα and Hβ. This double structure in the response curves – of two separate inner and outer components – has also been seen in the rms line profiles. We conclude that the outer and inner line segments originate in different regions and/or under different physical conditions.
Key words: galaxies: active / galaxies: Seyfert / galaxies: nuclei / galaxies: individual: Mrk 926 / quasars: emission lines
© ESO, 2010
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.