J/A+A/565/A71 NGC1068 MIDI/VLTI observations (Lopez-Gonzaga+, 2014)
Revealing the large nuclear dust structures in NGC1068 with MIDI/VLTI.
Lopez-Gonzaga N., Jaffe W., Burtscher L., Tristram K.R.W., Meisenheimer K.
<Astron. Astrophys. 565, A71 (2014)>
=2014A&A...565A..71L 2014A&A...565A..71L
ADC_Keywords: Active gal. nuclei ; Interferometry
Keywords: techniques: interferometric - galaxies: active - galaxies: nuclei -
galaxies: Seyfert - galaxies: individual: NGC1068 -
radiation mechanisms: thermal
Abstract:
The aim of this paper is to understand the relation in active galactic
nuclei (AGNs) between the small obscuring torus and dusty structures
at larger scales (5-10pc).
The dusty structures in AGNs are best observed in the mid-infrared. To
achieve the necessary spatial resolution (20-100 milliarcsec) we use
ESO's Mid-Infrared Interferometer (MIDI) with the 1.8m Auxiliary
Telescopes. We use the chromatic phases in the data to improve the
spatial fidelity of the analysis.
Description:
The low spatial frequency interferometric observations of NGC 1068
were carried out using the 1.8m Auxiliary Telescopes (AT's) together
with the MID-infrared interferometric Instrument (MIDI) at the
European Southern Observatory's (ESO's) Very Large Telescope
Interferometer (VLTI) on Cerro Paranal, Chile.
Observations were carried out on Visitor Mode on the nights of October
7 and 8, 2007 and September 19, 20, and 23-26, 2012. In total, 40
correlated fluxes measured under good weather conditions were reduced
and calibrated. For this paper, we also use previous interferometric
observations performed with the 8m - Unit Telescopes (UT's). The UT
data was previously published as part of an AGN Large Program
(Burtscher et al., 2013A&A...558A.149B 2013A&A...558A.149B).
Since our primary observable is not the visibility but the "correlated
flux" we have stored our data in a modified OIFITS file similar to the
data of Burtscher et al. (2013A&A...558A.149B 2013A&A...558A.149B), details about not
using visibilities and the total flux are explained in the paper.
"Correlated fluxes" are not yet part of the OIFITS specification
(version 1) the attached data includes a new field CFLUX/CFLUXERR that
contains the fluxes for the correlated fluxes. The VISAMP/VISAMPERR
fields were filled intentionaly with zero's. If visibilities want to
be used we suggest to contact the authors. The CFLUX/CFLUXERR fields
are built with the OIFITS standard but are ignored by strict OIFITS
viewers; oirgetvis() routine included in MIA+EWS will read these
fields correctly.
Objects:
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RA (2000) DE Designation(s)
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02 42 40.77 -00 00 47.8 NGC 1068 = M 77
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb.dat 67 79 Log of observations of NGC 1068
list.dat 48 1 List of UVFITS file
fits/* . 1 Individual UVFITS file (in OIFITS)
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Byte-by-byte Description of file: tableb.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 "date" Obs.date Observation date
12- 15 A4 --- Inst Instrument
17- 24 A8 "h:m:s" Obs.time Time of fringe track observation
26- 29 F4.1 m BL Projected baseline length
31- 35 F5.1 deg PA Position angle
37- 43 A7 --- Cal Calibrator name
45- 52 A8 "h:m:s" Caltime Time of the calibrator fringe track
observation
54- 56 F3.1 --- AirM Airmass of fringe track
58- 60 F3.1 arcsec See Seeing during fringe track observation
62 I1 --- Q [0/1] Goodness of observation (1=good, 0=bad)
64 I1 --- Stacked [0/1]?=- Stacked with the following
observation (yes:1, no:0)
66- 67 I2 --- Gr [1/11]?=- Group number according to criterion
of Sect. 4.1
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Byte-by-byte Description of file: list.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 F7.4 deg RAdeg Right ascension (J2000)
8- 15 F8.5 deg DEdeg Declination (J2000)
17- 34 A18 --- FileName Name of the file in subdirectory fits
36- 48 A13 --- Title Title of the file
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Acknowledgements:
Noel Lopez Gonzaga, nlopez( at )strw.leidenuniv.nl,
Leiden Observatory, Leiden University
(End) Patricia Vannier [CDS] 25-Mar-2014