MALBET , Fabien

Classical Be stars are hot non-supergiant stars surrounded by a gaseous circumstellar disk that is responsible for the observed infrared (IR) excess and emission lines. The influence of binarity on these phenomena remains controversial. We followed the evolution of the environment surrounding the binary Be star $\delta$ Scorpii one year before...

We present the design and realization of the AMBER data simulator. This tool provides the AMBER team with: (1) a way to test the performance and sensitivity of AMBER wrt. external parameters (e.g., observed source magnitude, AO correction); (2) a means to validate proposed visibility retrieval algorithms; and (3) a mean to obtain realistic data...

The AMBER instrument installed at the Very Large Telescope (VLT) combines three beams from as many telescopes to produce spectrally dispersed fringes from milli-arcsecond angular scale in the near infrared. Two years after installation, first scientific observations have been carried out during the Science Demonstration Time and the Guaranteed...

We present here the current performances of the AMBER / VLTI instrument for standard use and compare these with the offered modes of the instrument. We show that the instrument is able to reach its specified precision only for medium and high spectral resolution modes, differential observables and bright objects. For absolute observables, the...

AMBER is the near-IR instrument for the VLTI, which will offer the possibility of combining two or three beams from either the 8 meter VLT main telescopes or the 1.8 meter auxiliary telescopes. With spectral dispersion up to 10,000 high visibility accuracy and the ability to obtain closure phases, AMBER will offer the means to perform high...

Aims. We aim to study the geometry and kinematics of the disk around the Be star $\alpha$ Arae as a function of wavelength, especially across the Br$\gamma$ emission line. The main purpose of this paper is to answer the question about the nature of the disk rotation around Be stars. Methods. We use the VLTI/AMBER instrument operating in the K...

AMBER is the near-infrared instrument of the Very Large Telescope Interferometer (VLTI). With a spectral resolution up to 10000 in the 1.2-2.4 micron wavelength range, AMBER will offer the possibility to combine 3 beams from the VLTI array either 8-m or 1.8m telescopes. The instrument has been designed to bring high precision measurement and...

AMBER had first light in March 2004. The guaranteed time observations of the AMBER consortium (LAOG, MPIfR, OAA, OCA, UNSA) consists of 87 proposals ranging from cosmology, extragalactic studies, star formation, planetary system, late stages of stellar evolution to physical properties of stars. Some examples, AGN, evolved stars and hot stars...