J/A+A/558/A149 VLTI/MIDI AGN Large Program observations (Burtscher+, 2013)
A diversity of dusty AGN tori. Data release for the VLTI/MIDI AGN Large Program
and first results for 23 galaxies.
Burtscher L., Meisenheimer K., Tristram K.R.W., Jaffe W., Honig S.F.,
Davies R.I., Kishimoto M., Pott J.-U., Rottgering H., Schartmann M.,
Weigelt G., Wolf S.
<Astron. Astrophys. 558, A149 (2013)>
=2013A&A...558A.149B 2013A&A...558A.149B
ADC_Keywords: Active gal. nuclei ; Interferometry
Keywords: techniques: interferometric - galaxies: active - galaxies: nuclei -
galaxies: Seyfert - infrared: galaxies -
techniques: high angular resolution
Abstract:
The AGN-heated dust distribution (the "torus") is increasingly
recognized not only as the absorber required in unifying models, but
as a tracer for the reservoir that feeds the nuclear Super-Massive
Black Hole. Yet, even its most basic structural properties (such as
its extent, geometry and elongation) are unknown for all but a few
archetypal objects.
In order to understand how the properties of AGN tori are related to
feeding and obscuration, we need to resolve the matter distribution on
parsec scales.
Since most AGNs are unresolved in the mid-infrared, even with the
largest telescopes, we utilize the MID-infrared interferometric
Instrument (MIDI) at the Very Large Telescope Interferometer (VLTI)
that is sensitive to structures as small as a few milli-arcseconds
(mas). We present here an extensive amount of new interferometric
observations from the MIDI AGN Large Program (2009-2011) and add data
from the archive to give a complete view of the existing MIDI
observations of AGNs. Additionally, we have obtained high-quality
mid-infrared spectra from VLT/VISIR to provide a precise total flux
reference for the interferometric data.
We present correlated and total fluxes for 23 AGNs (16 of which with
new data) and derive flux and size estimates at 12m using simple
axisymmetric geometrical models.
Description:
All interferometric observations were carried out with MIDI, the
MID-infrared interferometric Instrument at the European Southern
Observatory's (ESO's) Very Large Telescope Interferometer (VLTI) on
Cerro Paranal, Chile.
The MIDI AGN Large Program (ESO program number 184.B-0832) consisted
of 13.1 nights of Visitor Mode observations. Between December 2009 and
August 2011, in total 228 science fringe track observations of 15 AGNs
have been observed in this program. For this paper, we also include
from the archive 159 previously observed tracks for these sources, 156
fringe tracks of other weak AGNs and 132 tracks for the two mid-IR
brightest AGNs (NGC 1068 and the Circinus galaxy). The observing logs
of each galaxy can be upload in the subdirectory log.
OIFITS is the standard for the exchange of reduced optical
interferometry data. It is an IAU accepted standard and defined in
Pauls et al. (2005PASP..117.1255P 2005PASP..117.1255P).
Since we use a special observing technique, detailed in the paper, our
primary observable is not the visibility but the "correlated flux".
This is not yet part of the OIFITS specification (version 1), but is
currently discussed for OIFITS version 2.0
(http://ipag.obs.ujf-grenoble.fr/twiki/bin/view/Jmmc/OIFITSTwoProject#
Proposalforcorrelated_flux). For the attached data I include both
the standard VISAMP/VISAMPERR fields which is the corr. flux divided
by the spectrum used for this source (from VISIR, if available, for
all sources except Mrk 1239, see the paper) and also new
CFLUX/CFLUXERR fields that are proposed for OIFITS version 2.0. These
fields comply with the FITS standard and are ignored by strict OIFITS
viewers; less strict OIFITS readers like MIA+EWS's oirgetvis() routine
will read these fields. For NGC 1068, I have downsampled the early
GRISM observations to PRISM resolution so that they can be combined in
one file.
The total flux can be retrieved from CFLUX/VISAMP and its error from
flux * sqrt((VISAMPERR/VISAMP)2 - (CFLUXERR/CFLUX)2).
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 112 25 The 23 Large Program and archive targets
tablea2.dat 67 27 VISIR mid-IR spectroscopy of LP sources
(Large Program 086.B-0919)
log.dat 111 666 Log of MIDI observations (tables a3-a28)
fits/* . 23 Individual OIFITS file for the 23 Large Program
galaxies
log/* . 23 Individual files of log of MIDI observations
(tables a3-a28) in LaTeX
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See also:
VII/258 : Quasars and Active Galactic Nuclei (13th Ed.) (Veron+ 2010)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Seq [1/23]? Running sequence number
4- 18 A15 --- Name Galaxy name
20- 21 I2 h RAh Hour of right ascension (J2000)
23- 24 I2 min RAm Minute of right ascension (J2000)
26- 29 F4.1 s RAs Second of right ascension (J2000)
31 A1 --- DE- Sign of declination (J2000)
32- 33 I2 deg DEd Degree of declination (J2000)
35- 36 I2 arcmin DEm Arcminute of declination (J2000)
38- 39 I2 arcsec DEs Arcsecond of declination (J2000)
41- 47 A7 --- Type AGN type as classified by Veron-Cetty
& Veron 2010 (Cat. VII/258)
49- 54 A6 --- Type2 AGN type from SIMBAD
56- 60 F5.1 Mpc Dist [3.8/546] Angular-size distance
62- 67 F6.4 --- z [0.001/0.16] Redshift from NED
69- 72 F4.1 mas/pc Scale Scale
74- 75 I2 arcsec psi [0/50] Coude (MACAO) guide star separation
from science target (0=guiding on nucleus)
77- 80 F4.1 mag Vmag V-band magnitude of guide star
82- 83 I2 --- Nuv [0/38] Number of good fringe tracks at
unique (u, v) positions
85- 90 A6 --- Ref Reference(s) (1)
92-112 A21 --- FileName Name of the OIFITS file in subdirectory fits
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Note (1): References as follows:
0 = Jaffe et al. (2004Natur.429...47J 2004Natur.429...47J)
1 = Meisenheimer et al. (2007A&A...471..453M 2007A&A...471..453M)
2 = Tristram et al. (2007, PhD thesis, Max-Planck-Institut fur Astronomie,
Konigstuhl 17, 69117 Heidelberg, Germany)
3 = Beckert et al. (2008A&A...486L..17B 2008A&A...486L..17B)
4 = Kishimoto et al. (2009A&A...493L..57K 2009A&A...493L..57K)
5 = Raban et al. (2009MNRAS.394.1325R 2009MNRAS.394.1325R)
6 = Tristram et al. (2009A&A...502...67T 2009A&A...502...67T)
7 = Burtscher et al. (2009ApJ...705L..53B 2009ApJ...705L..53B)
8 = Burtscher et al. (2010PASA...27..490B 2010PASA...27..490B)
9 = Tristram & Schartmann (2011A&A...531A..99T 2011A&A...531A..99T)
10 = Kishimoto et al. (2011A&A...536A..78K 2011A&A...536A..78K)
11 = Honig et al. (2012ApJ...755..149H 2012ApJ...755..149H)
12 = this work
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Byte-by-byte Description of file: tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Galaxy name
17- 20 F4.1 um Set [8.5/12.4] Setting
22- 31 A10 "YYYY-MM-DD" Obs.date Observing date
32 A1 --- --- [T]
33- 37 A5 "h:m" Obs.time Observing time
39- 46 A8 --- Cal Calibrator
48- 57 A10 --- Prog Program
59- 67 A9 --- Ref Reference
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Byte-by-byte Description of file: log.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Galaxy name
17- 26 A10 "YYYY-MM-DD" Date Observation date (date of night begin)
28- 31 A4 --- Inst Instrument (D0/E0/G0/H0/U1/U2/U3/U4)
33- 40 A8 "h:m:s" Time Time of fringe track observation
42- 43 I2 --- s [0/1]?=-1 Stacked with following
observation (yes: 1, no: 0)
45- 49 I5 --- NDIT [2000/16000] number of frames
51- 53 I3 --- BL [0/130] Projected baseline length
55- 59 F5.1 deg PA [0/180]? Projected baseline position angle
61 A1 --- g [P/G] grism setting (PRISM or GRISM)
63- 67 A5 --- Mode MIDI observing mode ("FT_OF" or "OBS_F")
69- 71 F3.1 --- am [0/3] airmass of fringe track
73- 75 F3.1 --- see [0.4/3.2] seeing during fringe
track observation
77- 78 I2 --- Oft ?=-1 Goodness of observation
(O: good:1, bad:0, N.A: -1)
80- 84 I5 --- NGood [0/11500]?=- Number of good frames
86- 90 F5.2 --- o3 ?=-1 Ozone absorption depth of associated
photometry observation
(-1: photometry does not exist)
92- 94 A3 --- A/B Number of A/B photometry observations
96- 97 I2 --- Oph [-1/1] Goodness of photometry observation
99-106 A8 "h:m:s" Ctime ? Time of calibrator observation
108-111 F4.1 --- Dam ? Difference in airmass between calibrator
observation and science observation
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Acknowledgements:
Leonard Burtscher, burtscher( at )mpe.mpg.de,
Max Planck institute for Extraterrestrial physics
(End) Patricia Vannier [CDS] 25-Oct-2013