scholarly journals A family portrait of disk inner rims around Herbig Ae/Be stars

2020 ◽  
Vol 636 ◽  
pp. A116 ◽  
Author(s):  
J. Kluska ◽  
J.-P. Berger ◽  
F. Malbet ◽  
B. Lazareff ◽  
M. Benisty ◽  
...  

Context. 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 that are located within the first au around their host star. Aims. We aim to reveal the morphology of the disk inner rim using near-infrared interferometric observations with milli-arcsecond resolution provided by near-infrared multitelescope interferometry. Methods. We provide model-independent reconstructed images of 15 objects selected from the Herbig AeBe survey carried out with PIONIER at the Very Large Telescope Interferometer, using the semi-parametric approach for image reconstruction of chromatic objects. We propose a set of methods to reconstruct and analyze the images in a consistent way. Results. We find that 40% of the systems (6/15) are centrosymmetric 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 noncentrosymmetric morphology due to a nonaxisymmetric and possibly variable environment (4/15, ~27%). Among the systems with a disk-like structure, 20% (3/15) show a resolved dust-free cavity. Finally, we do not detect extended emission beyond the inner rim. Conclusions. 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 or complex brightness distributions). Moreover, the nonaxisymmetric 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 a few weeks. The evidence of nonaxisymmetric emission that cannot be explained by simple inclination and radiative transfer effects requires 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.

2013 ◽  
Vol 8 (S299) ◽  
pp. 117-118 ◽  
Author(s):  
J. Kluska ◽  
F. Malbet ◽  
J.-P. Berger ◽  
M. Benisty ◽  
B. Lazareff ◽  
...  

AbstractThe close environment of Herbig stars starts to be revealed step by step and it appears to be quite complex. Many physical phenomena interplay: the dust sublimation causing a puffed-up inner rim, a dusty halo, a dusty wind or an inner gaseous component. To investigate more deeply these regions, getting images at the first Astronomical Unit scale is necessary. This has become possible with near infrared instruments on the VLTI. We have developed a new imaging method adapted to young stellar objects where we process separately the stellar component from the rest of the image to reveal the environment by using the spectral differences between these two components. We present the result of this method on the first imaging survey of Herbig stars carried out by PIONIER on the VLTI.


1999 ◽  
Vol 513 (2) ◽  
pp. L131-L134 ◽  
Author(s):  
R. Millan-Gabet ◽  
F. P. Schloerb ◽  
W. A. Traub ◽  
F. Malbet ◽  
J. P. Berger ◽  
...  

1987 ◽  
Vol 122 ◽  
pp. 125-126
Author(s):  
R. Carballo ◽  
C. Eiroa ◽  
A. Mampaso

We present accurate positions and near infrared photometry (Table I) of 11 point-like objects in the neighbourhood of GGD objects obtained on the 1.55 m and on the 1.23 m in Teide Obs. and Calar Alto Obs. respectively, in Spain. Several of the near infrared sources are directly associated with the GGD nebulae and/or are candidate for their excitation. In addition some of them seem to be the near infrared counterparts of IRAS sources. We believe, on the basis of their infrared excess, far infrared emission (IRAS), association with nebulosity, coincidence with H2O masers or the fact that in most cases the observed luminosities are higher than those expected for main sequence stars, that most of them (9/12) are young stars embedded in the dark clouds which contain the GGD objects. The loci of the detected sources in an (H-K,K-L) infrared two-colour diagram is the same as that obtained for known pre-main sequence stars, such as T Tauris and Herbig Ae-Be stars, indicating the presence of dust shells with temperatures in the range 800–1500 K. The observed range in luminosity, 10–4600 L⊙, added to other different characteristics found between them, such' as the presence, or absence, of H2O masers, indicates the interest for a detailed study of the infrared sources and related GGD nebulae.


2019 ◽  
Vol 141 (50) ◽  
pp. 19570-19574 ◽  
Author(s):  
Gary J. Richards ◽  
Aël Cador ◽  
Shinji Yamada ◽  
Anna Middleton ◽  
Whitney A. Webre ◽  
...  

2021 ◽  
Vol 417 ◽  
pp. 129271
Author(s):  
Haojun Yu ◽  
Jian Chen ◽  
Ruiyu Mi ◽  
Juyu Yang ◽  
Yan-gai Liu

2021 ◽  
Vol 866 ◽  
pp. 158568
Author(s):  
Jiaming Liu ◽  
Xin Huang ◽  
Heng Pan ◽  
Xu Zhang ◽  
Xiujie Fang ◽  
...  

Author(s):  
Xue Zhou ◽  
Jinmeng Xiang ◽  
Jiming Zheng ◽  
Xiaoqi Zhao ◽  
Hao Suo ◽  
...  

Near-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs) light source have great potential in non-destructive detection, promoting plant growth and night vision applications, while the discovery of a broad-band NIR phosphor still...


Polyhedron ◽  
2021 ◽  
pp. 115165
Author(s):  
Jian Gou ◽  
Qian-Qi Yang ◽  
Si-Yu Li ◽  
Li-Hua Zhao ◽  
Hong-Ling Gao ◽  
...  

2021 ◽  
Author(s):  
Wenxia Yin ◽  
Lingyi Meng ◽  
Tianjun Yu ◽  
Jinping Chen ◽  
Rui Hu ◽  
...  

Crystallization process of a NIR emissive supramolecular polymer formed by host–guest complexation of a distyrylanthracene derivative and cucurbiturils is described.


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