Speckle imaging of NGC 1068 and NGC 4151 in the forbidden O III 5007 A line and nearby continuum

Ebstein, Steven M.; Carleton, N. P.; Papaliolios, C.

doi:10.1086/166997

Cited by 21 publications

(12 citation statements)

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“…Although the image of the outer parts of the galaxy is not without value, only the nuclear region is well exposed, and only that region will be discussed here. In comparing the deconvolved images with the speckle reconstruction at similar continuum wavelengths by Ebstein et al (1989), it is clear that the present material takes resolution of the inner structure a step further. In simplest terms, we can clearly distinguish two separate new features: an irregular cloudlike structure and a "central" knot of significantly higher surface brightness.…”

Section: Discussionmentioning

confidence: 82%

“…The southern component is a little west of due south from the central component, and the northern component lies to the northeast. These features may have optical counterparts in the speckle reconstructions of Ebstein, Carleton, & Papaliolios (1989).…”

Section: L31mentioning

confidence: 95%

“…Among the several emission-line investigations since that time are those attempting to resolve the discrete clouds by means of speckle interferometry. One by Ebstein, Carleton, & Papaliolios (1989) in the light of [0 III] A.5007 shows the most consistency among diverse sets of observational data and reveals several discrete sources in addition to one which may arguably be called the nucleus. One speckle reconstruction for 5500 A continuum light shows mainly a central source elongated asymmetrically in the NE-SW direction.…”

Section: L31mentioning

confidence: 99%

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NGC 1068 - Resolution of nuclear structure in the optical continuum

Lynds

Faber²,

Light³

et al. 1991

ApJ

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An optical continuum image of the Seyfert galaxy NGC 1068 has been obtained with the Planetary Camera on the Hubble Space Telescope as part of the SAO/ERO program. The filter used, F547M, has an effective wavelength and a width of approximately 5470 and 650 A and excludes all discrete emission lines that might be present. The point-spread function, although compromised by the aberrations of the telescope optics, does permit significant response at the 0':1 resolution originally anticipated. Deconvolution of the image for the effects of the point-spread function reveals a bright nucleus embedded in an irregular cloudlike structure which is well differentiated against the background of the galaxy. The nucleus is resolved, with a FWHM of ~0':15, or 11 pc and there is no evidence for any unresolved nuclear component. The lack of an unresolved point source is consistent with the picture in which the broad-line region is seen indirectly via electron scattering, but the precise geometry of the scattering region cannot yet be inferred. The cloud surrounding the nucleus is elongated in the NE-SW direction and has extreme dimensions of 3':5 x 1':7 (255 x 124 pc). Although the extent of the cloud is roughly centered on the nucleus, its brightness centroid is situated 0':4 southwest of the nucleus. Because of the relative photometric dominance of the cloud with respect to both the nucleus and the underlying galaxy and the corresponding dominance of unpolarized star light found by Antonucci and Miller, the conclusion seems inescapable that the light from the cloud is contributed largely by stars. But in appearance the cloud is distinctly dissimilar to our expectation for either young or old stellar systems, and it seems to bear no simple relationship to the numerous features that have heretofore been resolved at other optical, infrared, and radio wavelengths. A determination of the true nature of both the cloud and the nuclear feature through spectroscopic and polarimetric measurements is of the highest priority.

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Section: Discussionmentioning

confidence: 82%

Section: L31mentioning

confidence: 95%

Section: L31mentioning

confidence: 99%

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NGC 1068 - Resolution of nuclear structure in the optical continuum

Lynds

Faber²,

Light³

et al. 1991

ApJ

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“…Ebstein et al (1989) found a bipolar structure of this object in the [OIII] emission line. Observations of this object corroborated with theoretical modeling like radiative transfer calculations have made signiffcant contributions on its structure.…”

Section: Active Galactic Nucleimentioning

confidence: 75%

Astronomical optical interferometry, II: Astrophysical results

Jankov

2011

SERBIAN ASTRON J

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Optical interferometry is entering a new age with several ground- based long-baseline observatories now making observations of unprecedented spatial resolution. Based on a great leap forward in the quality and quantity of interferometric data, the astrophysical applications are not limited anymore to classical subjects, such as determination of fundamental properties of stars; namely, their effective temperatures, radii, luminosities and masses, but the present rapid development in this field allowed to move to a situation where optical interferometry is a general tool in studies of many astrophysical phenomena. Particularly, the advent of long-baseline interferometers making use of very large pupils has opened the way to faint objects science and first results on extragalactic objects have made it a reality. The first decade of XXI century is also remarkable for aperture synthesis in the visual and near-infrared wavelength regimes, which provided image reconstructions from stellar surfaces to Active Galactic Nuclei. Here I review the numerous astrophysical results obtained up to date, except for binary and multiple stars milliarcsecond astrometry, which should be a subject of an independent detailed review, taking into account its importance and expected results at microarcsecond precision level. To the results obtained with currently available interferometers, I associate the adopted instrumental settings in order to provide a guide for potential users concerning the appropriate instruments which can be used to obtain the desired astrophysical information

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“…The VLTI sensitivity will allow to explore spatial scales which have not been probed so far, thus opening a new window on extragalactic astronomy. Previous observations of extragalactic sources have been limited to speckle interferometry of a few of the brightest Active Galactic Nuclei like NGC 1068 (Meaburn et al, 1982;Chelli et al, 1987;Afanas'ev et al, 1992;Wittkowski et al, 1998;Weinberger et al, 1999), NGC 1386 (Mauder et al, 1992) and NGC 4151 (Ebstein et al, 1989;Ayers et al, 1990). Even with the use of the 8m telescopes, VLTI observations will be limited to the brightest sources.…”

Section: Introductionmentioning

confidence: 99%

Extragalactic Astronomy with the VLTI: A New Window on the Universe

Marconi

Maiolino

Petrov

2003

The Very Large Telescope Interferometer Challenges for the Future

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Abstract. Interferometry in the optical and near infrared has so far played a marginal role in Extragalactic Astronomy. Active Galactic Nuclei are the brightest and most compact extragalactic sources, nonetheless only a very limited number could be studied with speckle interferometry and none with long baseline interferometry. The VLTI will allow the study of moderately faint extragalactic objects with very high spatial resolution thus opening a new window on the universe. With this paper we focus on three scientific cases to show how AMBER and MIDI can be used to tackle open issues in extragalactic astronomy.

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Speckle imaging of NGC 1068 and NGC 4151 in the forbidden O III 5007 A line and nearby continuum

Cited by 21 publications

References 0 publications

NGC 1068 - Resolution of nuclear structure in the optical continuum

NGC 1068 - Resolution of nuclear structure in the optical continuum

Astronomical optical interferometry, II: Astrophysical results

Extragalactic Astronomy with the VLTI: A New Window on the Universe

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