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Astron. Astrophys. 361, 901-912 (2000)
Strong spectral variability in NGC 7603 over 20 years *
W. Kollatschny 1,2,
K. Bischoff 1 and
M. Dietrich 3
1 Universitäts-Sternwarte Göttingen, Geismarlandstrasse 11, 37083 Göttingen, Germany
2 Department of Astronomy and McDonald Observatory, University of Texas at Austin, Austin, TX 78712, USA
3 Department of Astronomy, University of Florida, 211 Bryant Space Center, Gainesville, FL 32611-2055, USA
Received 14 June 2000 / Accepted 21 July 2000
Abstract
We present results of a long-term optical variability campaign on
the Seyfert 1 galaxy NGC 7603 over a period of nearly 20
years. The optical continuum and the Balmer and Helium lines varied by
a factor of 5 to 10 in this broad-line Seyfert 1 galaxy.
Furthermore, it is remarkable that the optical FeII line blends varied
with the same amplitude as the H![[FORMULA]](img1.gif)
and
HeI lines. During the first half of the campaign (until 1990) there
was a strong correlation between Balmer decrement variations,
H![[FORMULA]](img2.gif)
intensity variations and emission
line asymmetry. This behaviour changed afterwards when the
H line intensity was higher than on
average.
Key words: line:
profiles 
galaxies: individual:
NGC 7603
galaxies: Seyfert
* Based on observations taken at the German-Spanish Astronomical Centre Calar Alto, ESO, and McDonald Observatory
Send offprint requests to: W. Kollatschny (wkollat@uni-sw.gwdg.de)
Contents
- 1. Introduction
- 2. Observations and data reduction
- 3. Results and discussion
- 3.1. Line and continuum variations
- 3.2. UV spectra
- 3.3. CCF analysis
- 3.4. Line profile shapes and variations
- 3.5. Balmer decrement
- 4. Summary
- Acknowledgements
- References
© European Southern Observatory (ESO) 2000
Online publication: October 10, 2000
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