NICCOLINI , Gilles

The physical interpretation of spectro-interferometric data is strongly model-dependent. On one hand, models involving elaborate radiative transfer solvers are too time consuming in general to perform an automatic fitting procedure and derive astrophysical quantities and their related errors. On the other hand, using simple geometrical models...

Context: B[e] stars are expected to possess dusty circumstellar environments, which are responsible for a strong infrared (IR) excess. Aims: Using single-dish diffraction-limited imaging in the thermal infrared domain, we aim at measuring the angular extension of the dusty environment of the galactic B[e] MWC 300. Methods: We obtained...

Cepheids are the keystone of the extragalactic distance ladder because their pulsation periods correlate directly with their luminosity, through the Period-Luminosity (PL) relation (Leavitt & Pickering 1912). The discovery of the accelerated expansion of the Universe (Riess et al. 1998; 2011 Nobel prize) is largely based on the Cepheid PL...

ABSTRACT We present continuum and molecular-line (CO, C18O, HCO+) observations carried out with the Atacama Large Millimeter/submillimeter Array toward the 'water fountain' star IRAS 15103–5754, an object that could be the youngest planetary nebula (PN) known. We detect two continuum sources, separated by 0.39 ± 0.03 arcsec. The emission from...

B[e] supergiants are luminous, massive post-main sequence stars exhibiting non-spherical winds, forbidden lines, and hot dust in a disc-like structure. The physical properties of their rich and complex circumstellar environment (CSE) are not well understood, partly because these CSE cannot be easily resolved at the large distances found for...

Recently available near-infrared interferometric data on late-type stars show a strong increase of diameter for asymptotic giant branch (AGB) stars between the K (2.0{-}2.4 mum) and L (3.4{-}4.1 mum) bands. Aiming at an explanation of these findings, we chose the objects alpha Orionis (Betelgeuse), SW Virginis, and R Leonis, which are of...