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Titolo:
DIFFRACTION-LIMITED 76-MAS SPECKLE MASKING OBSERVATIONS OF THE CORE OF NGC-1068 WITH THE SAO-6-M-TELESCOPE
Autore:
WITTKOWSKI M; BALEGA Y; BECKERT T; DUSCHL WJ; HOFMANN KH; WEIGELT G;
Indirizzi:
MAX PLANCK INST RADIOASTRON,HUGEL 69 D-53121 BONN GERMANY INST THEORET ASTROPHYS D-69121 HEIDELBERG GERMANY SPECIAL ASTROPHYS OBSERV KARACHAI CHERKESIA 357147 RUSSIA
Titolo Testata:
Astronomy and astrophysics
fascicolo: 3, volume: 329, anno: 1998,
pagine: 45 - 48
SICI:
0004-6361(1998)329:3<45:D7SMOO>2.0.ZU;2-U
Fonte:
ISI
Lingua:
ENG
Soggetto:
SGR-A-ASTERISK; GALAXY NGC-1068; VARIABILITY; SPECTRUM; NUCLEUS;
Keywords:
TECHNIQUES, INTERFEROMETRIC; GALAXIES, FUNDAMENTAL PARAMETERS; GALAXIES, NUCLEI; GALAXIES, PHOTOMETRY; GALAXIES, SEYFERT; GALAXIES, INDIVIDUAL, NGC 1068;
Tipo documento:
Letter
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
18
Recensione:
Indirizzi per estratti:
Citazione:
M. Wittkowski et al., "DIFFRACTION-LIMITED 76-MAS SPECKLE MASKING OBSERVATIONS OF THE CORE OF NGC-1068 WITH THE SAO-6-M-TELESCOPE", Astronomy and astrophysics, 329(3), 1998, pp. 45-48

Abstract

We present the first K-band bispectrum speckle interferometry of NGC 1068 with an angular resolution of 76 mas (similar to 5.5 pc). This angular resolution allows us to attribute the measured flux to only one of the nuclear sources seen at radio wavelengths. The observed decreasing visibility function suggests that the dominant central core is probably not an unresolved point source, but slightly resolved with a FWHM diameter of similar to 30 mas similar to 2 pc for an assumed Gaussian intensity distribution. This 30 mas object is possibly the nuclear torus and/or a scattering halo. We discuss different contributions to the observed K band flux. Between 5 GHz and the K-band the spectrum of this component is close to a nu(1/3) proportionality. In addition to the standard interpretation of a hot dust torus surrounding the nucleusof NGC 1068, one cannot exclude the possibility that a sizeable fraction of the nuclear flux reaches us via a scattering halo. This then would allow us to determine physical parameters of the nuclear source.

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Documento generato il 05/12/20 alle ore 23:49:46