The shape of broad-line profiles in active galactic nuclei

Kollatschny, W.; Zetzl, M.

doi:10.1051/0004-6361/201219411

Cited by 65 publications

(73 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…i) If the broad-line profiles in AGN are contaminated by turbulence or outflowing winds in the line-emitting region (Murray & Chiang 1997;Kollatschny & Zetzl 2013), the emission-line velocity dispersion (σ V ) may be increased, leading to an overestimate of the black hole mass by means of the virial product. However, this does not explain the case of Mrk110.…”

Section: Central Black Hole Mass and The Geometry Scaling Factor For mentioning

confidence: 99%

Modelling photometric reverberation data: a disk-like broad-line region and a potentially larger black hole mass for 3C 120

Núñez

Haas

Ramolla

et al. 2014

A&A

Self Cite

View full text Add to dashboard Cite

We consider photometric reverberation mapping, where the nuclear continuum variations are monitored via a broad-band filter and the echo of emission line clouds of the broad-line region (BLR) is measured with a suitable narrow-band (NB) filter. We investigate how an incomplete emission-line coverage by the NB filter influences the determination of the BLR size. This includes two basic cases: 1) a symmetric cut of the blue and red part of the line wings; and 2) the filter positioned asymmetrically to the line centre so that essentially a complete half of the emission line is contained in the NB filter. Under the assumption that the BLR is dominated by circular Keplerian orbits, we find that symmetric cutting of line wings may lead to overestimating the BLR size by less than 5%. The case of asymmetric half-line coverage, similar as for our data of the Seyfert 1 galaxy 3C 120, yields a BLR size with a bias of less than 1%. Our results suggest that any BLR size bias due to a narrow-band line cut in photometric reverberation mapping is small and in most cases negligible. We used well-sampled photometric reverberation mapping light curves with sharp variation features in both the continuum and the Hβ light curves to determine the geometry type of the Hβ BLR for 3C 120. Modelling of the light curve, under the assumption that the BLR is essentially virialised, argues against a spherical geometry and favours a nearly face-on disk-like geometry with an inclination i = 10 • ± 4 • and an extension from 22 to 28 light days. The low inclination may lead to a larger black hole mass M BH than that derived when using the average geometry scaling factor f = 5.5. We discuss deviations of Seyfert 1 galaxies from the M BH -σ * relation.

show abstract

Section: Central Black Hole Mass and The Geometry Scaling Factor For mentioning

confidence: 99%

Modelling photometric reverberation data: a disk-like broad-line region and a potentially larger black hole mass for 3C 120

Núñez

Haas

Ramolla

et al. 2014

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…This is important because of the small size of the BLR, which is not spatially resolvable with current telescopes or Gaia. The line profile depends on, among other factors, different potential cloud velocities, the BLR geometry, obscuration effects, and superimposed emission lines from different quasar regions (Kollatschny & Zetzl 2013). Rotational motions of the line emitting clouds due to the Doppler effect produce Gaussian line profiles (e.g., Peterson & Wandel 1999), and outflowing gas can cause Logarithmic profiles (e.g., Blumenthal & Mathews 1975).…”

Section: Gaia's High-resolution Spectra With the Rvsmentioning

confidence: 99%

“…Furthermore, turbulent motions in the outer accretion disk can explain Lorentzian line profiles (Goad et al 2012). The ratio of this turbulent motion and the rotational velocity allows to investigate the thickness of the accretion disk (Kollatschny & Zetzl 2013). In the end, the measured line shape depends on various velocity components.…”

Section: Gaia's High-resolution Spectra With the Rvsmentioning

confidence: 99%

“…Hence, one can calculate the black hole mass using the FWHM from the RVS and the time lag from BP/RP observations. For the detection of broad emission line FWHM, one has to consider turbulent motions, otherwise one would overestimate black hole masses (Kollatschny & Zetzl 2013). If we determine the BEL response to continuum variations, we could distinguish intrinsic BEL variability from continuum variability with the help of the RVS.…”

Section: Gaia's High-resolution Spectra With the Rvsmentioning

confidence: 99%

See 1 more Smart Citation

Exploration of quasars with theGaiamission

Proft

Wambsganß

2015

A&A

View full text Add to dashboard Cite

We analyze the opportunities in and limits to investigating quasars with the Gaia satellite by studying Gaia's low-and high-resolution quasar spectra, with consideration of their signal-to-noise ratios. Furthermore, we explore bright quasars from the Sloan Digital Sky Survey with broad emission lines (BELs) redshifted into the spectral range of Gaia's Radial Velocity Spectrograph (RVS). We find that Gaia low-resolution spectra of quasars enable a determination of equivalent widths, continuum variability, and the Baldwin effect. Additionally, it will be feasible to analyze BEL reverberation mapping with Gaia data for a small sample of objects. These quasars should have a high cadence of measurements or higher time lags due to large redshifts, high quasar luminosities, or selected lowionization lines. More than 500 known quasars will also get high-resolution spectra of individual BELs in the small wavelength range of the RVS. This allows an investigation of broad emission line shapes and their variabilities to get information on the spatial structure and kinematics of the broad line region. We identify six known variable SDSS quasars with BELs in the RVS that have interesting spectra for a potential intrinsic line variability investigation. However, the signal-to-noise ratio of the RVS is too small for studying narrow and broad absorption lines in quasar spectra.

show abstract

“…We also tried a two-component Guassian fit, as well as a rotationally broadened Lorentzian, following Kollatschny & Zetzl (2013).…”

Section: Modelmentioning

confidence: 99%

SALT long-slit spectroscopy of LBQS 2113-4538: variability of the Mg II and Fe II component

Hryniewicz

Czerny

Pych

et al. 2014

A&A

View full text Add to dashboard Cite

Context. The Mg II line is of extreme importance in intermediate redshift quasars since it allows us to measure the black hole mass in these sources and to use these sources as probes of the distribution of dark energy in the Universe, as a complementary tool to SN Ia. Aims. Reliable use of Mg II requires a good understanding of all the systematic effects involved in the measurement of the line properties, including the contamination by Fe II UV emission. Methods. We performed three spectroscopic observations of a quasar LBQS 2113-4538 (z = 0.956) with the SALT telescope, separated in time by several months and we analyze in detail the mean spectrum and the variability in the spectral shape. Results. We show that even in our good-quality spectra the Mg II doublet is well fit by a single Lorentzian shape. We tested several models of the Fe II pseudo-continuum and showed that one of them well represents all the data. The amplitudes of both components vary in time, but the shapes do not change significantly. The measured line width of LBQS 2113-4538 identifies this object as a class A quasar. The upper limit of 3% for the contribution of the narrow line region (NLR) to Mg II may suggest that the separation of the broad line region and NLR disappears in this class of objects.

show abstract

The shape of broad-line profiles in active galactic nuclei

Cited by 65 publications

References 50 publications

Modelling photometric reverberation data: a disk-like broad-line region and a potentially larger black hole mass for 3C 120

Modelling photometric reverberation data: a disk-like broad-line region and a potentially larger black hole mass for 3C 120

Exploration of quasars with theGaiamission

SALT long-slit spectroscopy of LBQS 2113-4538: variability of the Mg II and Fe II component

Contact Info

Product

Resources

About