Optical Continuum and Emission‐Line Variability of Seyfert 1 Galaxies

Peterson, B. M.; Wanders, I.; Bertram, R.; Hunley, J.; Pogge, Richard W.; Wagner, R. M.

doi:10.1086/305813

Cited by 272 publications

(364 citation statements)

References 42 publications

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“…Using the virial theorem, the mass of a black hole (M BH ) is (Peterson et al 1998;Wandel et al 1999) where ΔV FWHM is the orbital velocity at a radius R BLR of the BLR, and it is estimated by the width of the emission line (specifically, the variable part of the line); f is the factor that depends on the geometry of the BLR. Using a sample disk model for the Arp 102B BLR, one can use the relation derived in Onken et al (2004) …”

Section: Black Hole Mass In Arp 102bmentioning

confidence: 99%

Spectral optical monitoring of a double-peaked emission line AGN Arp 102B

Shapovalova

Popovic

Burenkov

et al. 2013

A&A

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Context. We present results of long-term (1987-2010) optical spectral monitoring of the broad-line radio galaxy Arp 102B, a prototype of an active galactic nucleus with double-peaked broad emission lines that are commonly assumed to be emitted from an accretion disk. Aims. To explore the structure of the broad-line region (BLR), we analyze the light-curves of the broad Hα and Hβ lines and the continuum flux. We aim to estimate the dimensions of the broad-line emitting regions and the mass of the central black hole. Methods. We used the cross correlation function to find lags between the lines and continuum variations. We investigated the correlation between line and continuum fluxes in more detail and explored periodical variations of the red-to-blue line flux ratio using Lomb-Scargle periodograms. Results. The line and continuum light-curves show several flare-like events. The fluxes in lines and in the continuum show no significant change (around 20%) during the monitored period. We found a weak correlation between the line and continuum flux variation that may indicate that the line variation is weakly connected with the variation of the central photoionization source. In spite of this weak line-continuum correlation, we estimated a time lag for Hβ of about 20 days using various methods. The correlation between the Hβ and Hα flux variation is significantly higher than that between the lines and continuum. During the monitored period, the Hβ and Hα lines show double-peaked profiles, and we found an indication for a periodical oscillation in the red-to-blue flux ratio of the Hα line. The estimated mass of the central black hole is ∼1.1 × 10 8 M , which agrees with the mass estimated from the M-σ * relation.

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Section: Black Hole Mass In Arp 102bmentioning

confidence: 99%

Spectral optical monitoring of a double-peaked emission line AGN Arp 102B

Shapovalova

Popovic

Burenkov

et al. 2013

A&A

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“…The latter groups used single-epoch spectra to estimate black hole masses and found that the M BH -σ relation of AGNs is shallower than that of quiescent galaxies. One of the main differences between reverberation and single-epoch black hole masses is that the former uses the width of the variable part of the broad emission line measured from root mean square (rms) spectra (Peterson et al 1998). Single-epoch emission-line widths show ∼25% variation when compared with the rms line widths (Vestergaard 2002).…”

Section: The Impact Of Mergers On the M Bh -σ Relationmentioning

confidence: 99%

Mergers in Double-Peaked [O Iii] Active Galactic Nuclei

Myers

Djorgovski

et al. 2011

ApJ

109

115

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As a natural consequence of galaxy mergers, binary active galactic nuclei (AGNs) should be commonplace. Nevertheless, observational confirmations are rare, especially for binaries with separations less than 10 kpc. Such a system may show two sets of narrow emission lines in a single spectrum owing to the orbital motion of the binary. We have obtained high-resolution near-infrared images of 50 double-peaked [O iii]λ5007 AGNs with the Keck II laser guide star adaptive optics system. The Sloan Digital Sky Survey sample is compiled from the literature and consists of 17 type-1 AGNs between 0.18 < z < 0.56 and 33 type-2 AGNs between 0.03 < z < 0.24. The new images reveal eight type-1 and eight type-2 sources that are apparently undergoing mergers. These are strong candidates of kpc-scale binary AGNs because they show multiple components separated between 0.6 and 12 kpc and often disturbed morphologies. Because most of the type-1s are at higher redshifts than the type-2s, the higher merger fraction of type-1s (47% ± 20%) compared to that of type-2s (24% ± 10%) can be attributed to the general evolution of galaxy merger fraction with redshift. Furthermore, we show that AGN mergers are outliers of the M BH -σ relation because of overestimated stellar velocity dispersions, illustrating the importance of removing mergers from the samples defining the M BH -σ relations. Finally, we find that the emission-line properties are indistinguishable for spatially resolved and unresolved sources, emphasizing that scenarios involving a single AGN can produce the same double-peaked line profiles and they account for at least 70% of the double-peaked [O iii] AGNs.

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“…The F W HM can be averaged on all spectra, giving a "mean" BH mass: this is the method preferred by Kaspi et al (2000). In the method proposed by Peterson et al (1998), the F W HM is measured on the rms spectrum, giving a "rms" mass.…”

Section: Relation Between the Optical Luminositymentioning

confidence: 99%

Size-mass-luminosity relations in AGN and the role of the accretion disc

Collin

Huré

2001

A&A

101

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Abstract.We address the question of the relations between the black hole's mass, the accretion rate, the bolometric luminosity, the optical luminosity and the size of the Broad Line Region (BLR) in Active Galactic Nuclei, using recent observational data obtained from monitoring campaigns. We first show that a standard accretion disc cannot account for the observed optical luminosity, unless it radiates at super-Eddington rates. This implies the existence of another, dominant emission mechanism in the optical range, which could be due to the reprocessing of X-rays by a system of dense clouds, or a non standard disc (non stationary, ADAF and/or strong outflows). Narrow Line Seyfert 1 galaxies (NLS1s) are most extreme in this context: they have larger bolometric to Eddington luminosity ratios than Broad Line Seyfert 1 (BLS1s), and most likely a larger "non disc" component in the optical range. Second, from realistic simulations of self-gravitating α-discs, we have systematically localized the gravitationally unstable disc and shown that, given uncertainties on both the model and observations, it coincides quite well with the size of the BLR. We therefore suggest that the gravitationally unstable disc is the source which releases BLR clouds in the medium. However, the influence of the ionization parameter is also required to explain the correlation found between the size of the BLR and the luminosity. In this picture, the size of the BLR in NLS1s (relative to the black hole size) is larger (and the emission line width smaller) than in BLS1s simply because their Eddington ratio is larger.

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Optical Continuum and Emission‐Line Variability of Seyfert 1 Galaxies

Cited by 272 publications

References 42 publications

Spectral optical monitoring of a double-peaked emission line AGN Arp 102B

Spectral optical monitoring of a double-peaked emission line AGN Arp 102B

Mergers in Double-Peaked [O Iii] Active Galactic Nuclei

Size-mass-luminosity relations in AGN and the role of the accretion disc

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