Bibcode
DOI
Bechtold, J.; Barker, E. S.; Balonek, T. J.; Peterson, B. M.; Younger, P. F.; Wills, D.; Wills, B. J.; Wilkes, B. J.; Weymann, R. J.; Turner, T. J.; Veilleux, S.; Wagner, R. M.; Smith, H. A.; Smith, P. S.; Sun, W.-H.; Thiele, U.; Shapovalova, A. I.; Smith, A. G.; Saddlemyer, L.; Sadun, A.; Sawyer, S. R.; Shields, J. C.; Richmond, M. W.; Romanishin, W.; Rosenblatt, E. I.; Pogge, R. W.; Penfold, J.; Penston, M. V.; Perez, E.; Netzer, H.; Oliveira, C. L. M.; Dietrich, M.; Elvis, M.; Ferguson, A.; Filippenko, A. V.; Fricke, K. J.; Gaskell, C. M.; Halpern, J. P.; Huchra, J. P.; Hutchings, J. B.; Kollatschny, W.; Koratkar, A. P.; Korista, K. T.; Krolik, J. H.; Lame, N. J.; Laor, A.; Leacock, R. J.; MacAlpine, G. M.; Malkan, M. A.; Maoz, D.; Miller, H. R.; Morris, S. L.; Cochran, A. L.; Cohen, R. D.; Crampton, D.; Christensen, J. A.; Clements, S. D.; Carini, M. T.; Carone, T. E.; Bond, D.; Boroson, T. A.; Bochkarev, N. G.; Bolte, M. J.; Bertram, R.
Bibliographical reference
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 368, Feb. 10, 1991, p. 119-137. Research supported by NSERC, American Astronomical Society, and USIBSF.
Advertised on:
2
1991
Journal
Citations
310
Refereed citations
260
Description
A large, international program of ground-based optical spectroscopy and
photometry of the variable Seyfert 1 galaxy NGC 5548 undertaken in
support of an IUE monitoring campaign is described. This contribution
presents the data base and describes the methods used to correct for
systematic differences between spectra from different sources. Optical
continuum and H-beta emission-line light curves are derived from the
spectra. The behavior of the optical continuum is qualitatively the same
as the behavior of the ultraviolet continuum. Cross-correlation of the
ultraviolet and optical continuum measurements does not reveal any
significant lag between them. The h-beta emission-line variations show
the same basic pattern as seen in the continuum and ultraviolet emission
lines, with H-beta lagging behind the continuum by about 20 days. This
is significantly larger than the about 10 day lag deduced for Ly-alpha.