VLTI/AMBER observations of the Seyfert nucleus of NGC 3783

Weigelt, G.; Hofmann, K.-H.; Kishimoto, M.; Hönig, S. F.; Schertl, D.; Marconi, A.; Millour, F.; Petrov, R.; Fraix-Burnet, Didier; Malbet, Fabien; Tristram, K.; Vannier, M.

doi:10.1051/0004-6361/201219213

Cited by 57 publications

(65 citation statements)

References 27 publications

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“…It has been extensively covered with near-and mid-IR interferometry. Hönig et al (2013) report simple modelling of 41 VLTI MIDI observations in the mid-IR and 6 VLTI AMBER measurements in the near-IR (AMBER data originally from Weigelt et al 2012). The IR SED shows the characteristic 3 − 5 µm bump with an estimated hotdust covering factor of about 30%.…”

Section: Polar Elongations In Type 1 Agn: Ngc3783 As a Case Studymentioning

confidence: 99%

Dusty Winds in Active Galactic Nuclei: Reconciling Observations with Models

Hönig

Kishimoto

2017

ApJL

168

239

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This letter presents a revised radiative transfer model for the infrared (IR) emission of active galactic nuclei (AGN). While current models assume that the IR is emitted from a dusty torus in the equatorial plane of the AGN, spatially resolved observations indicate that the majority of the IR emission from 100 pc in many AGN originates from the polar region, contradicting classical torus models. The new model CAT3D-WIND builds upon the suggestion that the dusty gas around the AGN consists of an inflowing disk and an outflowing wind. Here, it is demonstrated that (1) such disk+wind models cover overall a similar parameter range of observed spectral features in the IR as classical clumpy torus models, e.g. the silicate feature strengths and mid-IR spectral slopes, (2) they reproduce the 3 − 5 µm bump observed in many type 1 AGN unlike torus models, and (3) they are able to explain polar emission features seen in IR interferometry, even for type 1 AGN at relatively low inclination, as demonstrated for NGC3783. These characteristics make it possible to reconcile radiative transfer models with observations and provide further evidence of a two-component parsec-scaled dusty medium around AGN: the disk gives rise to the 3 − 5 µm near-IR component, while the wind produces the mid-IR emission. The model SEDs will be made available for download.

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Section: Polar Elongations In Type 1 Agn: Ngc3783 As a Case Studymentioning

confidence: 99%

Dusty Winds in Active Galactic Nuclei: Reconciling Observations with Models

Hönig

Kishimoto

2017

ApJL

168

239

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“…Several other analytical patterns of brightness distribution patterns have been employed to analyze different astrophysical objects (cf. Berger 2003) such as resolved stars (Dyck et al 1998;Ohnaka et al 2013), young supernovae (Marcaide et al 2009), recurrent novae (Chesneau et al 2007), protoplanetary disks (Malbet et al 2005), or active galaxies (Weigelt et al 2012). In all of these cases, successful fitting of a given brightness distribution pattern to visibility data is a strong prerequisite for recovering structural and physical information about the target object.…”

Section: Introductionmentioning

confidence: 99%

Brightness temperature constraints from interferometric visibilities

Lobanov

2015

A&A

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Context. The brightness temperature is an effective parameter that describes the physical properties of emitting material in astrophysical objects. It is commonly determined by imaging and modeling the structure of the emitting region and estimating its flux density and angular size. Aims. Reliable approaches for visibility-based estimates of brightness temperature are needed for interferometric experiments in which poor coverage of spatial frequencies prevents successful imaging of the source structure, for example, in interferometric measurements made at millimeter wavelengths or with orbiting antennas. Methods. Such approaches can be developed by analyzing the relations between brightness temperature and visibility amplitude and its rms error. Results. A method is introduced for directly calculating the lower and upper limits of the brightness temperature from visibility measurements. The visibility-based brightness temperature estimates are shown to agree well with the image-based estimates obtained in the 2 cm MOJAVE survey and the 3 mm CMVA survey, with good agreement achieved for interferometric measurements at spatial frequencies exceeding ≈2 × 10 8 . Conclusions. The method provides an essential tool for constraining brightness temperature in all interferometric experiments with poor imaging capability.

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“…Over the past years, convincing observational evidence has indicated that hot dust resides at the outer edge of the BLR (Barvainis 1987;Heisler et al 1997;Osterbrock & Ferland 2006), and with the rise of infrared interferometry, it has finally become feasible to directly resolve the near-infrared (NIR) hot dust around nearby Seyfert 1 AGNs (Swain et al 2003;Weigelt et al 2012). The observational data were essential in breaking degeneracies in radiative transfer models, resulting in the current overall picture: a clumpy distribution of dust clouds that accumulate along the equatorial plane and constitute the shape of a torus.…”

Section: Introductionmentioning

confidence: 99%

Dust physics in the nucleus of NGC 4151

Schnülle

Pott

Rix

et al. 2013

A&A

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The unified model of active galactic nuclei (AGNs) presumes the existence of a so-called dusty torus around the outer edge of the broad-line region. Despite the solid observational evidence for the existence of dust around AGNs and our growing information on the characteristic scales of these obscuring tori, the origin of this dust and its morphology are not yet well understood. Using dust reverberation mapping, we monitor the effects of AGN continuum variability to determine the temperature and covering factor of the circumnuclear dust, in order to constrain the physical conditions for dust survival and formation in the radiation field of the AGN. Multi-band photometry observations in the z, Y, J, H, and K bands were carried out on the nucleus of the prototypical Seyfert 1 galaxy NGC 4151 over six epochs from 2010 January to June, supported by spectroscopic observations, in order to investigate the response of the hot dust to varying accretion disk emission. Our data confirm that most of the hot dust reacts to increased radiation from the central source with a delayed brightening of ∼50 days. In accretion disk brightening, we see no signatures of dust destruction in our data. The innermost dust appears to increase in temperature rather than sublimate, suggesting that it is cooler than sublimation temperature and located beyond the current sublimation radius. We characterize the dust geometry by interpreting the wavelength-dependent reverberation response with a simplified torus model, pointing to a static radially extended distribution of the central (∼0.1 pc) hot dust.

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VLTI/AMBER observations of the Seyfert nucleus of NGC 3783

Cited by 57 publications

References 27 publications

Dusty Winds in Active Galactic Nuclei: Reconciling Observations with Models

Dusty Winds in Active Galactic Nuclei: Reconciling Observations with Models

Brightness temperature constraints from interferometric visibilities

Dust physics in the nucleus of NGC 4151

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