Student or educator? Sign up with your school email and get 6 months of Pro free.
CoChat
Sign Up
Cited by 238

The DOI matches its Crossref record.

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

Open access
Peterson, B. M., Balonek, T. J., Barker, E. S., Bechtold, J., Bertram, R., Bochkarev, N. G., Bolte, M. J., Bond, D., Boroson, T. A., Carini, M. T., Carone, T. E., Christensen, J. A., Clements, S. D., Cochran, A. L., Cohen, R. D., Crampton, D., 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., Netzer, H., Oliveira, C. L. M., Penfold, J., Penston, M. V., Perez, E., Pogge, R. W., Richmond, M. W., Romanishin, W., Rosenblatt, E. I., Saddlemyer, L., Sadun, A., Sawyer, S. R., Shields, J. C., Shapovalova, A. I., Smith, A. G., Smith, H. A., Smith, P. S., Sun, W.-H., Thiele, U., Turner, T. J., Veilleux, S., Wagner, R. M., Weymann, R. J., Wilkes, B. J., Wills, B. J., Wills, D., Younger, P. F.·1991·The Astrophysical Journal
DOI 10.1086/169675
Open this paper in CoChat — free account

Abstract

We report on 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 described by Clavel and coworkers. In this contribution, we present the data base and describe the methods used to correct for systematic differences between spectra from different sources. Optical continuum and Hβ 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 Hβ emission-line variations show the same basic pattern as seen in the continuum and ultraviolet emission lines, with Hβ lagging behind the continuum by ~ 20 days. This is significantly larger than the ~ 10 day lag deduced for Lyα.

Overview

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1086/169675

Cites

Statistics

Verification

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Citations

Cited by

See all 238

Metadata

Authors
Peterson, B. M., Balonek, T. J., Barker, E. S., Bechtold, J., Bertram, R., Bochkarev, N. G., Bolte, M. J., Bond, D., Boroson, T. A., Carini, M. T., Carone, T. E., Christensen, J. A., Clements, S. D., Cochran, A. L., Cohen, R. D., Crampton, D., 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., Netzer, H., Oliveira, C. L. M., Penfold, J., Penston, M. V., Perez, E., Pogge, R. W., Richmond, M. W., Romanishin, W., Rosenblatt, E. I., Saddlemyer, L., Sadun, A., Sawyer, S. R., Shields, J. C., Shapovalova, A. I., Smith, A. G., Smith, H. A., Smith, P. S., Sun, W.-H., Thiele, U., Turner, T. J., Veilleux, S., Wagner, R. M., Weymann, R. J., Wilkes, B. J., Wills, B. J., Wills, D., & Younger, P. F.
Venue
The Astrophysical Journal
Publisher
American Astronomical Society
Published
1991-02
Volume
368
Pages
119
ISSN
  • 0004-637X (ISSN-L)
  • 1538-4357
DOI
10.1086/169675
OpenAlex
W1489364622
Cited by
238
References
0
FWCI
21.46
Type
journal article
Language
en
Open access
green

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review

How to cite

Cite CoChat for the checks on this page, and the paper for its own findings.

This page
CoChat. (2026). Citation check: 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. https://app.cochat.ai/papers/10.1086/169675
The paper
Peterson, B. M., Balonek, T. J., Barker, E. S., Bechtold, J., Bertram, R., Bochkarev, N. G., Bolte, M. J., Bond, D., Boroson, T. A., Carini, M. T., Carone, T. E., Christensen, J. A., Clements, S. D., Cochran, A. L., Cohen, R. D., Crampton, D., Dietrich, M., Elvis, M., Ferguson, A., . . . Younger, P. F. (1991). 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. The Astrophysical Journal. https://doi.org/10.1086/169675

Data sources

Bibliographic data: Semantic Scholar, OpenAlex, Crossref.

Contains information from the Semantic Scholar Academic Graph Datasets, made available under the ODC Attribution License (ODC-BY 1.0).

Semantic Scholar’s data is described in: Kinney, R., et al. (2023). The Semantic Scholar Open Data Platform. arXiv:2301.10140.