Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. I - an 8 month campaign of monitoring NGC 5548 with IUE

Clavel, J.; Reichert, G. A.; Alloin, D.; Crenshaw, D. Michael; Kriss, G. A.; Krolik, Julian H.; Malkan, Matthew A.; Netzer, H.; Peterson, B. M.; Wamsteker, W.; Altamore, A.; Baribaud, T.; Barr, P.; Beck, S. C.; Binette, L.; Bromage, G. E.; Brosch, Noah; Díaz, Ángeles I.; Filippenko, A. V.; Fricke, K. J.; Gaskell, C. M.; Giommi, P.; Glass, Ian S.; Gondhalekar, P. M.; Hackney, R. L.; Halpern, J. P.; Hutter, D. J.; Jörsäter, S.; Kinney, A. L.; Kollatschny, W.; Koratkar, Anuradha; Korista, K. T.; Laor, Ari; Lasota, Jean–Pierre; Leibowitz, E. M.; Maoz, Dan; Martín, P. G.; Mazeh, T.; Meurs, E.; Nair, A. D.; O’Brien, P. T.; Pelat, D.; Pérez, E.; Perola, G. C.; Ptak, R.; Rodríguez-Pascual, P.; Rosenblatt, E. I.; Sadun, A. C.; Santos-Lleo, M.; Shaw, Richard A.; Smith, Paul S.; Stirpe, G. M.; Stoner, R.; Sun, Wei‐Hsin; Ulrich, M. H.; Groningen, E. van; Zheng, Wei

doi:10.1086/169540

Cited by 378 publications

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“…The variability parameters F var and R max have been calculated for the broad-band flux variations as well as for the broad emission lines and the optical continuum (cf. Clavel et al 1991;Rodríguez-Pascual et al 1997). The quantity R max is the ratio of the maximum to the minimum flux.…”

Section: Light Curvesmentioning

confidence: 99%

“…Peterson 1993;Netzer & Peterson 1997 for a review; Marshall et al 1997;Nandra et al 1998;Edelson et al 2000). Thus, over the last decade, several large space-based and ground-based monitoring programs have been undertaken for nearby AGN, such as NGC 5548 (Clavel et al 1991;Peterson et al 1991Peterson et al , 1992Peterson et al , 1994Peterson et al , 1999Maoz et al 1993;Dietrich et al 1993;Korista et al 1995;Chiang et al 2000), NGC 3783 Stirpe et al 1994;Alloin et al 1995), NGC 4151 Kaspi et al 1996;Warwick et al 1996;Edelson et al 1996), Fairall 9 (Rodríguez-Pascual et al 1997Santos-Lleó et al 1997), 3C 390.3 (Leighly et al 1997;Dietrich et al 1998;O'Brien et al 1998), and NGC 7469 (Wanders et al 1997;Collier et al 1998).…”

Section: Introductionmentioning

confidence: 99%

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A spectroscopic and photometric study of short-timescale variability in NGC 5548

Dietrich

Bender

Bergmann

et al. 2001

A&A

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Abstract.Results of a ground-based optical monitoring campaign on NGC 5548 in June 1998 are presented. The broad-band fluxes (U , B, V ), and the spectrophotometric optical continuum flux F λ (5100Å) monotonically decreased in flux while the broad-band R and I fluxes and the integrated emission-line fluxes of Hα and Hβ remained constant to within 5%. On June 22, a short continuum flare was detected in the broad band fluxes. It had an amplitude of about ∼18% and it lasted only ≈90 min. The broad band fluxes and the optical continuum F λ (5100Å) appear to vary simultaneously with the EUV variations. No reliable delay was detected for the broad optical emission lines in response to the EUVE variations. Narrow Hβ emission features predicted as a signature of an accretion disk were not detected during this campaign. However, there is marginal evidence for a faint feature at λ 4962Å with F W HM 6Å redshifted by ∆v 1100 km s −1 with respect to Hβnarrow.

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Section: Light Curvesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A spectroscopic and photometric study of short-timescale variability in NGC 5548

Dietrich

Bender

Bergmann

et al. 2001

A&A

Self Cite

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“…The ranges of radius corresponding to different lines are systematically offset from each other by sizable amounts (e.g. Clavel et al 1991, Krolik et al 1991. And the whole structure may change in timescales as short as a few years (Peterson & Wanders 1996).…”

Section: Broad Linesmentioning

confidence: 99%

A Unified View of How the Study of Emission Lines Furthers Our Knowledge of AGN

Krolik

1997

International Astronomical Union Colloquium

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Abstract. A global view is given of how emission lines have been, and may in the future, be used to enhance our understanding of AGN. Lines from the microwave to the X-ray bands all contribute. Although we have a deep understanding of the physical processes by which line photons are generated, when the circumstances of line emission are complicated, models become too unreliable to provide strong inferences about the rest of the AGN system. At present, the lines which appear the most promising for helping answer the most important questions about AGN are the 22 GHz H 2 O rotational transition and the 6.4 keV Fe Kα fluorescence.

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“…The BLRs of these objects are sometimes detected in polarized light, suggesting that the broad-line emission in these objects has been scattered back in our line-of-sight by electrons and/or dust located above and below the torus (Antonucci and Miller 1985;Miller and Goodrich 1990;Tran et al 1992). Because of the small size of the BLR (R flight-months; Clavel et al 1991;Peterson et al 1991), the exact location and velocity field of the broad-line gas is not well-determined. It may be associated with the disk itself and simply rotating around the central object and/or it could be outflowing along the rotation axis of the torus.…”

Section: Distribution Of the Line-emitting Gas In Active Galaxiesmentioning

confidence: 99%

The line-emitting gas in active galaxies - A probe of the nuclear engine

Veilleux¹

1993

PASP

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ABSTRACT. This paper reviews some of the basic questions regarding the structure of the engine powering active galactic nuclei (AGN), the nature of the interaction between the AGN and the host galaxy, and the origin and evolution of AGN. The study of the dynamics and physical characteristics of the line-emitting gas in these objects has proven fruitful in addressing many of these issues. Recent advances in optical and infrared detector technology combined with the development of superior ground-based instruments have produced efficient new tools for the study of the line-emitting gas on nuclear (R % 1 pc) and galactic {R £ 50 pc) scales. Programs which take advantage of two of these new techniques, Fabry-Perot imaging spectroscopy and infrared spectroscopy, are described in this paper. The origin of nuclear activity in galaxies is also addressed in a third project which aims at determining the nature of luminous infrared galaxies.

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Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. I - an 8 month campaign of monitoring NGC 5548 with IUE

Cited by 378 publications

References 0 publications

A spectroscopic and photometric study of short-timescale variability in NGC 5548

A spectroscopic and photometric study of short-timescale variability in NGC 5548

A Unified View of How the Study of Emission Lines Furthers Our Knowledge of AGN

The line-emitting gas in active galaxies - A probe of the nuclear engine

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