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Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. II - an intensive study of NGC 5548 at optical wavelengths

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1991

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10.1086/169675

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IOP Publishing
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Peterson, B. M., T. J. Balonek, E. S. Barker, J. Bechtold, R. Bertram, N. G. Bochkarev, M. J. Bolte, et al. 1991. “Steps Toward Determination of the Size and Structure of the Broad-Line Region in 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.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.Active Galactic Nuclei. II - an Intensive Study of NGC 5548 at Optical Wavelengths.” The Astrophysical Journal 368 (February): 119. doi:10.1086/169675.

Abstract

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.

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http://adsabs.harvard.edu/abs/1991ApJ...368..119P

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Active Galactic Nuclei, Galactic Structure, Seyfert Galaxies, Astronomical Photometry, Astronomical Spectroscopy, Emission Spectra, Iue, Light Curve, Visible Spectrum

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http://nrs.harvard.edu/urn-3:HUL.InstRepos:30212173

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