J/A+A/636/A116 VLTI/PIONIER images of 15 Herbig Ae/Be stars (Kluska+, 2020)
A family portrait of disk inner rims around Herbig Ae/Be stars.
Hunting for warps, rings, self shadowing, and misalignments in the inner
astronomical units.
Kluska J., Berger J.-P., Malbet F., Lazareff B., Benisty M.,
Le Bouquin J.-B., Absil O., Baron F., Delboulbe A., Duvert G., Isella A.,
Jocou L., Juhasz A., Kraus S., Lachaume R., Menard F., Millan-Gabet R.,
Monnier J.D., Moulin T., Perraut K., Rochat S., Pinte C., Soulez F.,
Tallon M., Thi W.-F., Thiebaut E., Traub W., Zins G.
<Astron. Astrophys. 636, A116 (2020)>
=2020A&A...636A.116K 2020A&A...636A.116K (SIMBAD/NED BibCode)
ADC_Keywords: YSOs ; Stars, early-type ; Interferometry
Keywords: stars: variables: T Tauri, Herbig Ae/Be -
techniques: interferometric - techniques: high angular resolution -
protoplanetary disks - circumstellar matter -
stars: pre-main sequence
Abstract:
The innermost astronomical unit (au) in protoplanetary disks is a key
region for stellar and planet formation, as exoplanet searches have
shown a large occurrence of close-in planets, located within the first
au around their host star.
We aim to reveal the morphology of the disk inner rim using
near-infrared interferometric observations with milli-arcsecond
resolution provided by near-infrared multi-telescope interferometry.
Methods: We provide model-independent reconstructed images of 15
objects selected from the Herbig AeBe survey carried out with
VLTI/PIONIER, using the semi-parametric approach for image
reconstruction of chromatic objects (SPARCO). We propose a set of
methods to reconstruct and analyze the images in a consistent way.
40% of the systems (6/15) are found to be centro-symmetric at the
angular resolution of the observations. For the rest of the objects,
we find evidence for asymmetric emission due to moderate-to-strong
inclination of a disk-like structure for ∼30% of the objects (5/15),
and non-centro-symmetric morphology due to an non-axisymmetric and
possible variable environment (4/15, ∼27%). Among the systems with
disk-like structure, 20% (3/15) show a resolved dust-free cavity.
Finally, we do not detect extended emission beyond the inner rim.
The image reconstruction process is a powerful tool to reveal complex
disk inner rim morphologies which is complementary to the fit of
geometrical models. At the angular resolution reached by near-infrared
interferometric observations most of the images are compatible with a
centrally peaked emission (no cavity). For the most resolved targets,
image reconstruction reveals morphologies that cannot be reproduced by
generic parametric models (e.g., perturbed inner rims, complex
brightness distributions). Moreover, the non-axisymmetric disks show
that the spatial resolution probed by optical interferometers makes
the observations of the near-infrared emission (inside a few au)
sensitive to temporal evolution with a time-scale down to few weeks.
The evidence of non-axisymmetric emission that cannot be explained by
simple inclination and radiative transfer effects requires for
alternative explanations such as a warping of the inner disks.
Interferometric observations can therefore be used to follow the
evolution of the asymmetry of those disks at an au or sub-au scale.
Description:
Reconstructed images for VLTI/PIONIER in the H band for 15 Herbig
Ae/Be stars: HD37806, HD45677, MWC158, HD98922, HD100453, HD100546,
HD142527, HD144432, HD144668, HD145718, HD150193, HD163296, MWC297, VV
Ser and R CrA. The images are normalized so the total flux equals
unity. The star is located at the centre (0, 0). The chromatic
parameters fs and denv are indicated as FSVAL and DEVAL keywords in
the header of the fits files. The central wavelength is 1.65 microns.
The regularisation weight used is indicated in the MUVAL header. The
noise maps associated with the images are included in the fits files.
To reproduce the observed visibilities one should use equation 2 of
the paper.
The images were done using SPARCO image reconstruction approach
(Kluska et al., 2014A&A...564A..80K 2014A&A...564A..80K
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 84 15 List of fits images
fits/* . 15 Individual fits images
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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- 9 A9 --- Star Star name
11- 12 I2 h RAh Simbad right ascension (J2000)
14- 15 I2 min RAm Simbad right ascension (J2000)
17- 21 F5.2 s RAs Simbad right ascension (J2000)
23 A1 --- DE- Simbad declination sign (J2000)
24- 25 I2 deg DEd Simbad declination (J2000)
27- 28 I2 arcmin DEm Simbad declination (J2000)
30- 33 F4.1 arcsec DEs Simbad declination (J2000)
35- 37 I3 --- Nx Number of pixels along X-axis
39- 41 I3 --- Ny Number of pixels along Y-axis
43- 45 I3 Kibyte size Size of FITS file
47- 65 A19 --- FileName Name of FITS file, in subdirectory fits
67- 84 A18 --- Title Title of the FITS file
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Acknowledgements:
Jacques Kluska, jacques.kluska(at)kuleuven.be
(End) Patricia Vannier [CDS] 18-Mar-2020