J/A+A/617/A83 MIDI atlas of low- and intermediate-mass YSOs (Varga+, 2018)
VLTI/MIDI atlas of disks around low- and intermediate-mass young stellar
objects.
Varga J., Abraham P., Chen L., Ratzka T., Gabanyi K.E., Kospal A.,
Matter A., van Boekel R., Henning T., Jaffe W., Juhasz A., Lopez B.,
Menu J., Moor A., Mosoni L., Sipos N.
<Astron. Astrophys. 617, A83 (2018)>
=2018A&A...617A..83V 2018A&A...617A..83V (SIMBAD/NED BibCode)
ADC_Keywords: Atlases ; Interferometry ; Infrared sources ; Spectra, infrared ;
Stars, pre-main sequence ; YSOs
Keywords: protoplanetary disks - stars: pre-main sequence -
techniques: interferometric - circumstellar matter - infrared: stars
Abstract:
Protoplanetary disks show large diversity regarding their morphology
and dust composition. With mid-infrared interferometry the thermal
emission of disks can be spatially resolved, and the distribution and
properties of the dust within can be studied.
Our aim is to perform a statistical analysis on a large sample of 82
disks around low- and intermediate-mass young stars, based on
mid-infrared interferometric observations. We intend to study the
distribution of disk sizes, variability, and the silicate dust
mineralogy.
Archival mid-infrared interferometric data from the MIDI instrument on
the Very Large Telescope Interferometer are homogeneously reduced and
calibrated. Geometric disk models are used to fit the observations to
get spatial information about the disks. An automatic spectral
decomposition pipeline is applied to analyze the shape of the silicate
feature.
We present the resulting data products in the form of an atlas,
containing N band correlated and total spectra, visibilities, and
differential phases. The majority of our data can be well fitted with
a continuous disk model, except for a few objects, where a gapped
model gives a better match. From the mid-infrared size-luminosity
relation we find that disks around T Tauri stars are generally colder
and more extended with respect to the stellar luminosity than disks
around Herbig Ae stars. We find that in the innermost part of the
disks (r≲1au) the silicate feature is generally weaker than in the
outer parts, suggesting that in the inner parts the dust is
substantially more processed. We analyze stellar multiplicity and find
that in two systems (AB Aur and HD 72106) data suggest a new companion
or asymmetric inner disk structure. We make predictions for the
observability of our objects with the upcoming Multi-AperTure mid-
Infrared SpectroScopic Experiment (MATISSE) instrument, supporting the
practical preparations of future MATISSE observations of T Tauri
stars.
Description:
This atlas presents mid-infrared interferometric spectra of 82 low-
and intermediate-mass young stellar objects (YSOs). The data were
taken from the archive of the Mid-infrared Interferometric Instrument
(MIDI) on the Very Large Telescope Interferometer. Our sample contains
82 objects, of which 45 are T Tauri stars, 11 are young eruptive
stars, and 26 are Herbig Ae stars. Observation dates range from 2003
to 2015. We homogeneously reduced and calibrated the interferometric
data using the Expert Work Station (EWS) package 2.0 software. The
atlas contains correlated spectra, total spectra, squared
visibilities, and differential phases in the 7.5-13{micro}m
wavelength range. Data between 9.4 and 10.0 {micro}m can be heavily
affected by the atmospheric ozone absorption feature, especially in
the total spectra. Data are presented in OIFITS version 2 format. The
OIFITS files contain all spectra in all epochs for each object: the
OI_VIS2 table contains the squared visibilities, the OI_VIS table
contains the correlated spectra (VISAMP column, Jy) and the
differential phases (VISPHI column, deg), and the OI_FLUX table
contains the total spectra (Jy). Additionally, we present here the
results of the interferometric modeling of the objects, which can be
used to get spatial information about the circumstellar disks.
Additional material (figures, ascii data files) can be found on the
project webpage at http://konkoly.hu/MIDI_atlas/.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 141 82 Overview of the sample
table2.dat 174 77 Results of the interferometric model fitting
tablee1.dat 69 703 Overview of the MIDI observations
refs.dat 67 75 References
fits/* . 82 Individual OIFITS files
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq [1/82] Running sequence number
4- 13 A10 --- Name Name of the star
15- 23 F9.5 deg RAdeg Right ascension in decimal degrees (J2000)
25- 33 F9.5 deg DEdeg Declination in decimal degrees (J2000)
35- 42 A8 --- Type YSO type (1)
44- 49 F6.1 pc Dist Distance to star (2)
51- 55 F5.1 pc e_Dist ? Error in Dist
57- 58 A2 --- SpType Spectral type (SIMBAD)
60- 66 F7.2 Lsun Lum ? Stellar luminosity (3)
68- 73 F6.2 Lsun e_Lum ? Error in Lum
75- 79 F5.2 mag AV ? Interstellar extinction (3)
81- 84 F4.2 mag e_AV ? Error in AV
86-101 A16 --- Ref References to the distance and photometric
data (see refs.dat file)
103-117 A15 --- FileName Name of OIFITS file in subdirectory fits
119-141 A23 --- SimbadName Name of the star in SIMBAD
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Note (1): YSO types as follows:
TT = T Tauri
HAe = Herbig Ae
embHAe = embedded Herbig Ae
eruptive = eruptive star (FUor or EXor)
TT/HAe = intermediate type between the T Tauri and Herbig Ae classes
Note (2): Distances were taken partly from the Gaia DR1 catalog, and partly
from the literature.
Note (3): Stellar luminosities and AV values are calculated from our SED
modeling. We fitted the SEDs with Kurucz-models (Castelli & Kurucz,
2004A&A...419..725C 2004A&A...419..725C) using the SED fitter code by Robitaille et al.
(2007A&A...464..541R 2007A&A...464..541R). For the fitting we collected optical (U, B, V, R, I),
and near-IR (J, H, K) photometric data from the literature. References to
these data are listed in column Ref.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq [1/82] Running sequence number
4- 13 A10 --- Name Name of the star
15- 20 F6.4 AU Rsub Dust sublimation radius (1)
22- 27 F6.3 Jy Ftot Total flux of the continuous model
29- 33 F5.3 Jy e_Ftot Error in Ftot (lower)
35- 39 F5.3 Jy E_Ftot Error in Ftot (upper)
41- 45 F5.3 --- q Temperature-gradient of the continuous
model (2)
47- 51 F5.3 --- e_q Error in q (lower)
53- 57 F5.3 --- E_q Error in q (upper)
59- 64 F6.3 AU Rhl Half-light radius of the continuous model
66- 70 F5.3 AU e_Rhl Error in Rhl (lower)
72- 78 F7.3 AU E_Rhl Error in Rhl (upper)
80- 84 F5.2 --- chi2 Chi2-value of the continuous model
86- 90 F5.3 --- qgap ? Temperature-gradient of the gapped
model (2)
92- 96 F5.3 --- e_qgap ? Error in qgap (lower)
98-102 F5.3 --- E_qgap ? Error in qgap (upper)
104-109 F6.3 AU Rin ? Inner radius of the gapped model
111-116 F6.3 AU e_Rin ? Error in Rin (lower)
118-123 F6.3 AU E_Rin ? Error in Rin (upper)
125-130 F6.3 AU Rhlgap ? Half-light radius of the gapped model
132-137 F6.3 AU e_Rhlgap ? Error in Rhlgap (lower)
139-144 F6.3 AU E_Rhlgap ? Error in Rhlgap (upper)
146-150 F5.2 --- chi2gap ? Chi2-value of the gapped model
152-174 A23 --- SimbadName Name of the star in SIMBAD
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Note (1): The sublimation radius is calculated from the stellar luminosity,
assuming a sublimation temperature of 1500K.
Note (2): The temperature-gradient (q, qgap) is the power-law exponent of the
temperature profile.
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Byte-by-byte Description of file: tablee1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Name of the star
12- 27 A16 --- Date Date of observation (YYYY-MM-DDThh:mm)
29- 33 A5 --- Base Baseline configuration
35- 39 F5.1 m Bproj Projected baseline length
41- 45 F5.1 deg PA Projected baseline position angle
47- 51 F5.1 AU Res Resolution at 10.7 {micro}m (1)
53- 65 A13 --- ProgID ESO Program ID
67 I1 --- Flag ? Observation flag (2)
69 A1 --- Sil [e a w] Silicate feature (3)
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Note (1): Resolution is given as the FWHM of a fringe, converted to physical
scale.
Note (2): The observation flag marks low-quality (unreliable) datasets.
Note (3): Characterization of the 10 {micro}m silicate feature in the correlated
spectra, based on our automatic spectrum analysis as follows:
e = silicate emission
a = silicate absorption
w = weak feature or flat spectrum
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- Ref Reference code
4- 22 A19 --- BibCode Bibcode
24- 44 A21 --- Aut Author's name
46- 75 A30 --- Com Comments
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Acknowledgements:
Jozsef Varga, varga.jozsef(at)csfk.mta.hu
(End) Jozsef Varga [Konkoly Obs.], Patricia Vannier [CDS] 07-May-2018