Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. III - Further observations of NGC 5548 at optical wavelengths

Peterson, B. M.; Alloin, D.; Axon, D. J.; Balonek, T. J.; Bertram, R.; Boroson, Todd A.; Christensen, J. A.; Clements, S. D.; Dietrich, M.; Elvis, M.; Filippenko, A. V.; Gaskell, C. M.; Haswell, C. A.; Huchra, J. P.; Jackson, N.; Kollatschny, W.; Korista, K. T.; Lame, N. J.; Leacock, R. J.; Lin, Shin-Yi; Malkan, Matthew A.; Monk, A. S.; Penston, M. V.; Pogge, Richard W.; Robinson, A.; Rosenblatt, E. I.; Shields, J. C.; Smith, Alex; Stirpe, G. M.; Sun, Wei‐Hsin; Turner, T. J.; Wagner, R. M.; Wilkes, B. J.; Wills, Beverley J.

doi:10.1086/171447

Cited by 48 publications

(43 citation statements)

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“…We use the time delay measurements of Hβ emission line summarized in Du et al (2015Du et al ( , 2016, which are compiled from the reverberation campaigns performed by different groups (Barth et al 2013, 2009b, 2014, Collier et al 1998, Dietrich et al 1993, 2015, Kaspi et al 2000, Pei et al 2014, Peterson et al 1991, 1992, 2002, 2014, Santos-Lleó et al 1997, 2001, Stirpe et al 1994, Wang et al 2014. The time delays represent the emissivity-weighted radii of the BLR in those RM objects.…”

Section: Observational Datamentioning

confidence: 99%

A Test of the Formation Mechanism of the Broad Line Region in Active Galactic Nuclei

Czerny

Wang

et al. 2016

ApJ

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The origin of the Broad Line Region (BLR) in active galaxies remains unknown. It seems to be related to the underlying accretion disk but an efficient mechanism is required to rise the material from the disk surface without giving too strong signatures of the outflow in the case of the low ionization lines. We discuss in detail two proposed mechanisms: (i) radiation pressure acting on dust in the disk atmosphere creating a failed wind (ii) the gravitational instability of the underlying disk. We compare the predicted location of the inner radius of the BLR in those two scenarios with the observed position obtained from the reverberation studies of several active galaxies. The failed dusty outflow model well represents the observational data while the predictions of the self-gravitational instability are not consistent with observations. The issue remains why actually we do not see any imprints of the underlying disk instability in the BLR properties.

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Section: Observational Datamentioning

confidence: 99%

A Test of the Formation Mechanism of the Broad Line Region in Active Galactic Nuclei

Czerny

Wang

et al. 2016

ApJ

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“…continuum light curves. The continuum region at 5100 Å has widely been used in studies of many AGNs, such as the prototype Seyfert galaxy NGC 5548 (Peterson et al 1992). The spectral range between 5130 and 5140 Å was found to be a more appropriate continuum region in the narrow-line Seyfert galaxy Mrk 110 (Kollatschny et al 2003).…”

Section: Continuum and Emission-line Light Curvesmentioning

confidence: 99%

Line profile and continuum variability in the very broad-line Seyfert galaxy Mrk 926

Kollatschny

Zetzl

2010

A&A

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Aims. We present results of an intensive spectroscopic variability campaign of the very broad-line Seyfert 1 galaxy Mrk 926. Our aim is to investigate the broad-line region (BLR) by studying the intensity and line profile variations of this galaxy on short timescales. Methods. High signal-to-noise ratio (S/N) spectra were taken with the 9.2 m Hobby-Eberly Telescope (HET) in identical conditions during two observing campaigns in 2004 and 2005. After the spectral reduction and internal calibration we achieved a relative flux accuracy of better than 1%. Results. The rms profiles of the very broad Balmer lines have shapes that differ from their mean line profiles, consisting of two inner (v ±6000 km s −1 ) and two outer (v ±6000 km s −1 ) line components in addition to a central component (v ±600 km s −1 ). These outer and inner line segments varied with different amplitudes during our campaign. The radius of the BLR is very small with an upper limit of 2 light-days for the Hβ BLR size. We derived an upper limit to the central black hole mass of M = 11.2 × 10 7 M . The 2-D cross-correlation functions CCF(τ, v) of Hβ and Hα are flat within the error limits. The response of the Balmer line segments with respect to continuum variations is different in the outer and inner wings of Hα and Hβ. This double structure in the response curves -of two separate inner and outer components -has also been seen in the rms line profiles. We conclude that the outer and inner line segments originate in different regions and/or under different physical conditions.

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“…8 × 12. 8) F ([O III] 5007Å) = 5.1 to 5.9 10 −13 erg s −1 cm −2 is mentioned (Peterson et al 1992). To be constistent with the Hβ line flux measurements of NGC 5548 obtained since 1988 ) we adopted…”

Section: Optical Spectroscopymentioning

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%

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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Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. III - Further observations of NGC 5548 at optical wavelengths

Abstract: The Open University's repository of research publications and other research outputs Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. III-Further observations of NGC 5548 at optical wavelengths

Cited by 48 publications

References 0 publications

A Test of the Formation Mechanism of the Broad Line Region in Active Galactic Nuclei

A Test of the Formation Mechanism of the Broad Line Region in Active Galactic Nuclei

Line profile and continuum variability in the very broad-line Seyfert galaxy Mrk 926

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

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