J/A+A/663/A151 HD 169142 VLT/VISIR images (Devinat+, 2022)
Radial distribution of the carbonaceous nano-grains in the protoplanetary disk
around HD 169142.
Devinat M., Habart E., Pantin E., Ysard N., Jones A., Labadie L.,
Di Folco E.
<Astron. Astrophys. 663, A151 (2022)>
=2022A&A...663A.151D 2022A&A...663A.151D (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Spectroscopy
Keywords: protoplanetary disks - radiative transfer - methods: data analysis -
techniques : imaging spectroscopy
Abstract:
HD 169142 is part of the class of (pre-)transitional protoplanetary
disks showing multiple carbon nanodust spectroscopic signatures
(aromatic, aliphatic) dominating the infrared spectrum. Precise
constraints on the spatial distribution and properties of carbonaceous
dust particles are essential to understanding the physics, radiative
transfer processes, and chemistry of the disk. The HD 169142 disk is
seen almost face-on and thus it offers a unique opportunity to study
the dust radial evolution in disks.
We investigate the spatial distribution of the carriers of several
dust aromatic emission features of the disk across a broad spatial
range (10-200AU) as well as their properties.
We analyse imaging and spectroscopic observations in the 8-12um range
from the VLT Imager and Spectrometer for mid-Infrared (VISIR) at the
Very Large Telescope (VLT), as well as adaptive optics spectroscopic
observations in the 3-4µm range from Nasmyth Adaptive Optics
System - Near-Infrared Imager and Spectrograph (NACO) at VLT. The data
probe the spatial variation of the flux in the 3.3µm, 8.6µm, and
11.3µm aromatic bands. To constrain the radial distribution of
carbonaceous nano-grains, the observations were compared to model
predictions using The Heterogeneous dust Evolution Model for
Interstellar Solids (THEMIS), which is integrated into the POLARIS
radiative transfer code by calculating the thermal and stochastic
heating of micro-and nanometer-sized dust grains for a given disk
structure.
Our data show show predominant nano-particle emission at all radii
(accessible with our resolution of about 0.1" or ∼12AU at 3um and
∼0.3", 35AU at 10um) in the HD 169142 disk. This unambiguously shows
that carbonaceous nano-grains dominate radiatively the infrared
spectrum in most of the disk, a finding that has been suggested in
previous studies. In order to account for both VISIR and NACO emission
maps, we show the need for aromatic particles distributed within the
disk from the outermost regions to a radius of 20AU, corresponding to
the outer limit of the inner cavity derived from previous
observations. In the inner cavity, these aromatic particles might be
present but their abundance would then be significantly decreased.
Description:
Emission maps of HD169142 are taken in imaging mode using VLT/VISIR in
the PAH1, PAH2, ArIII and SIV filters. All data were obtained under
fair conditions of seeing (less than 1 arcsec DIMM monitor) and
precipitable water content smaller than 5mm. Chopping-nodding technique
was used to remove the high-thermal background. All observations
except on the ArIII filter are in burst mode. All observations except
in the PAH1 filter have a pixel size of 0.075-arcsec (the pixel scale
in the PAH1 filter map is 0.046-arcsec). Names of the files :
VISIRimgHD169142_PAH1.fits, VISIRimgHD169142_PAH2.fits,
VISIRimgHD169142_ArIII.fits, VISIRimgHD169142_SIV.fits.
Emission maps of standard stars using VLT/VISIR in the PAH1 (star
HD 167121), PAH2 (star HD 151680), ArIII (star HD 151680) and SIV
(star HD 151680) filters provide PSF maps associated to the
observations of HD 169142. The maps have the same properties than
their science analogs in the respective filters. Names of the files :
VISIRimgPSF_PAH1.fits, VISIRimgPSF_PAH2.fits,
VISIRimgPSF_ArIII.fits, VISIRimgPSF_SIV.fits.
VISIR data acquired in spectral mode along a slit are provided. The
observing conditions were fair, at less than 0.8-arcsec optical seeing
and relatively low humidity. Spectral resolution is 220, and the slit
was north-south aligned, with a pixel size of 0.127". Chopping
and nodding were performed parallel to the slit. The data underwent
photometric calibration and telluric correction using standard star
(HD 177716) observations. Name of the file : 2DspectraJyas2.fits.
We provide NACO spectroimaging emission maps of HD 169142 between 3.2
and 3.76um, with a spectral resolution of 1000. The observed region
has an projected area of 2"*0.354" on the plane of sky. The emission
maps are continuum subtracted. The emission flux is given in Jy. The
pixel size is 0.042" : NACO_HD169142.fits.
Objects:
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RA (2000) DE Designation(s)
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18 24 29.78 -29 46 49.3 HD 169142 = EM* MWC 925
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 125 10 List of fits files
fits/* . 10 Individual fits files
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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 Simbad Right ascension (J2000) of target
4- 5 I2 min RAm Simbad Right ascension (J2000) target
7- 11 F5.2 s RAs Simbad Right ascension (J2000) target
12 A1 --- DE- Simbad declination sign (J2000) of target
13- 14 I2 deg DEd Simbad declination (J2000) of target
16- 17 I2 arcmin DEm Simbad declination (J2000) of target
19- 22 F4.1 arcsec DEs Simbad declination (J2000) of target
24- 27 I4 byte size Size of FITS file
29- 59 A31 --- FileName Name of FITS file, in subdirectory fits
61-125 A65 --- Title Title of the FITS file
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Acknowledgements:
Marie Devinat, marie.devinat(at)ens-paris-saclay.fr
(End) Patricia Vannier [CDS] 15-Mar-2022