J/A+A/663/A35 Circinus galaxy N-band VLTI/MATISSE images (Isbell+, 2022)
The dusty heart of Circinus. I. Imaging the circumnuclear dust in N-band.
Isbell J.W., Meisenheimer K., Pott J.-U., Stalevski M., Tristram K.R.W.,
Sanchez-Bermudez J., Hofmann K.-H., Gamez Rosas V., Jaffe W., Burtscher L.,
Leftley J., Petrov R., Lopez B., Henning T., Weigelt G., Allouche F.,
Berio P., Bettonvil F., Cruzalebes P., Dominik C., Heininger M.,
Hogerheijde M., Lagarde S., Lehmitz M., Matter A., Meilland A., Millour F.,
Robbe-Dubois S., Schertl D., van Boekel R., Varga J., Woillez J.
<Astron. Astrophys. 663, A35 (2022)>
=2022A&A...663A..35I 2022A&A...663A..35I (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Galaxies, Seyfert ; Infrared sources
Keywords: infrared: galaxies - galaxies: active - galaxies: Seyfert -
instrumentation: interferometers
Abstract:
Active galactic nuclei play a key role in the evolution of galaxies,
but their inner workings and physical connection to the host are
poorly understood due to a lack of angular resolution. Infrared
interferometry makes it possible to resolve the circumnuclear dust in
the nearby Seyfert 2 galaxy, the Circinus Galaxy. Previous
observations have revealed complex structures and polar dust emission
but interpretation was limited to simple models. The new Multi
AperTure mid-Infrared Spectro-Scopic Experiment (MATISSE) makes it
possible to image these structures for the first time.
We aim to precisely map the morphology and temperature of the dust
surrounding the supermassive black hole through interferometric
imaging.
We observed the Circinus Galaxy with MATISSE at the Very Large
Telescope Interferometer (VLTI), producing 150 correlated flux spectra
and 100 closure phase spectra. The novel inclusion of closure phases
makes interferometric imaging possible for the first time. We
reconstructed images in the N-band at ∼10mas resolution. We fit
blackbody functions with dust extinction to several aperture-extracted
fluxes from the images to produce a temperature distribution of
central dusty structures.
We find significant substructure in the circumnuclear dust: central
unresolved flux of ∼0.5Jy, a thin disk 1.9pc in diameter oriented
along ∼45°, and a 4 1.5pc polar emission extending orthogonal to
the disk. The polar emission exhibits patchiness, which we attribute
to clumpy dust. Flux enhancements to the east and west of the disk are
seen for the first time. We distinguish the temperature profiles of
the disk and of the polar emission: the disk shows a steep temperature
gradient indicative of denser material; the polar profile is flatter,
indicating clumpiness and/or lower dust density. The unresolved flux
is fitted with a high temperature, 370K. The polar dust remains warm
(∼200K) out to 1.5pc from the disk. We attribute approximately 60% of
the 12m flux to the polar dust, 10% to the disk, and 6% is
unresolved; the remaining flux was resolved out. The recovered
morphology and temperature distribution resembles modeling of
accretion disks with radiation-driven winds at large scales, but we
placed new constraints on the subparsec dust.
The spatially resolved subparsec features imaged here place new
constraints on the physical modeling of circumnuclear dust in active
galaxies; we show strong evidence that the polar emission consists of
dust clumps or filaments. The dynamics of the structures and their
role in the Unified Model remain to be explored.
Description:
Observations of the active galactic nucleus (AGN), Circinus, with
VLTI/MATISSE resulted in the reconstruction of images at seven
independent wavelength channels in the N-band. These images show the
circumnuclear dust and provide new details on constraints on the
structure commonly known as the AGN torus. The images were
reconstructed from 150 correlated flux and 100 closure phase
measurements obtained in March 2020, February 2021, and June 2021. The
images were reconstructed at 8.5, 8.9, 9.7, 10.5, 11.3, 12.0, and 12.7
micrometers. The images are given in Fig. 3 of the paper.
Objects:
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RA (2000) DE Designation(s)
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14 13 09.91 -65 20 20.5 Circinus = NAME Circinus Galaxy
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 93 7 List of fits images
fits/* . 7 Individual fits images
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See also:
J/A+A/549/A139 : Circinus galaxy CRIRES observations (Gnerucci+, 2013)
Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Right Ascension of center (J2000)
4- 5 I2 min RAm Right Ascension of center (J2000)
7- 11 F5.2 s RAs Right Ascension of center (J2000)
12 A1 --- DE- Declination sign of center (J2000)
13- 14 I2 deg DEd Declination of center (J2000)
16- 17 I2 arcmin DEm Declination of center (J2000)
19- 22 F4.1 arcsec DEs Declination of center (J2000)
24- 26 I3 --- Nx Number of pixels along X-axis
28- 30 I3 --- Ny Number of pixels along Y-axis
32- 33 I2 Kibyte size Size of FITS file
35- 51 A17 --- FileName Name of FITS file, in subdirectory fits
53- 93 A41 --- Title Title of the FITS file
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Acknowledgements:
Jacob Isbell, isbell(at)mpia.de, Max Planck Institute for Astronomy
(End) Jacob Isbell [Max Planck Inst. Ast.], Patricia Vannier [CDS] 09-May-2022