Publications (28)
Efficient Steering Mechanism for Mobile Network-enabled UAVs
H. Hellaoui, A. Chelli, M. Bagaa +1
The consideration of mobile networks as a communication infrastructure for unmanned aerial vehicles (UAVs) creates a new plethora of emerging services and opportunities. In particu…
Milli-arcsecond astrophysics with VSI, the VLTI spectro-imager in the ELT era
F. Malbet, D. Buscher, G. Weigelt +49
Nowadays, compact sources like surfaces of nearby stars, circumstellar environments of stars from early stages to the most evolved ones and surroundings of active galactic nuclei c…
Extrasolar planets and brown dwarfs around A-F type stars. II. A planet found with ELODIE around the F6V star HD 33564
F. Galland, A. M. Lagrange, S. Udry +4
We present here the detection of a planet orbiting around the F6V star HD 33564. The radial velocity measurements, obtained with the ELODIE echelle spectrograph at the Haute-Proven…
Search for optical microvariability in a large sample of Seyfert I galaxies
P. O. Petrucci, A. Chelli, G. Henri +3
We present results of an optical (I band) monitoring of a sample of 22 Seyfert I galaxies. We aimed to detect microvariability with time resolution from ~ 6 minutes down to 30 seco…
Phase closure nulling. Application to the spectroscopy of faint companions
A. Chelli, G. Duvert, F. Malbet +1
We provide a complete theory of the phase closure of a binary system in which a small, feeble, and unresolved companion acts as a perturbing parameter on the spatial frequency spec…
Single-Mode versus multimode interferometry: a performance study
E. Tatulli, P. Mege, A. Chelli
We compare performances of ground-based single-mode and multimode (speckle) interferometers in the presence of partial Adaptive Optics correction of atmospheric turbulence. It is f…
Mid-infrared circumstellar emission of the long-period Cepheid l Carinae resolved with VLTI/MATISSE
V. Hocdé, N. Nardetto, A. Matter +149
The nature of circumstellar envelopes (CSE) around Cepheids is still a matter of debate. The physical origin of their infrared (IR) excess could be either a shell of ionized gas, o…
AMBER Task Force February 2008 run report
F. Malbet, G. Duvert, A. Chelli +1
AMBER was installed in March 2004 in the VLTI focal lab of the VLT observatory in Cerro Paranal run by ESO. Since then, there have been 4 commissioning runs and additional VLTI inf…
Extrasolar planets and brown dwarfs around A-F type stars. I. Performances of radial velocity measurements, first analyses of variations
F. Galland, A. M. Lagrange, S. Udry +5
We present the performances of a radial velocity measurement method that we developed for A-F type stars. These perfomances are evaluated through an extensive set of simulations, t…
Extrasolar planets and brown dwarfs around A-F type stars III. Beta-Pictoris : looking for planets, finding pulsations
F. Galland, A. M. Lagrange, S. Udry +4
In the frame of the search for extrasolar planets and brown dwarfs around early-type stars, we present the results obtained on Beta-Pictoris, which is surrounded by a circumstellar…
DARWIN - A Mission to Detect, and Search for Life on, Extrasolar Planets
C. S. Cockell, A. Leger, M. Fridlund +47
The discovery of extra-solar planets is one of the greatest achievements of modern astronomy. The detection of planets with a wide range of masses demonstrates that extra-solar pla…
Direct constraint on the distance of y2 Velorum from AMBER/VLTI observations
F. Millour, R. G. Petrov, O. Chesneau +95
In this work, we present the first AMBER observations, of the Wolf-Rayet and O (WR+O) star binary system y2 Velorum. The AMBER instrument was used with the telescopes UT2, UT3, and…
The asymmetric inner disk of the Herbig Ae star HD 163296 in the eyes of VLTI/MATISSE: evidence for a vortex?
J. Varga, M. Hogerheijde, R. van Boekel +133
Context. The inner few au region of planet-forming disks is a complex environment. High angular resolution observations have a key role in understanding the disk structure and the…
Precise calibration of the dependence of surface brightness-colour relations on colour and class for late-type stars
A. Salsi, N. Nardetto, D. Mourard +9
Surface brightness-colour relations (SBCRs) are used to derive the stellar angular diameters from photometric observations. They have various astrophysical applications, such as th…
Phase closure nulling of HD 59717 with AMBER/VLTI . Detection of the close faint companion
G. Duvert, A. Chelli, F. Malbet +1
Aims: The detection of close and faint companions is an essential step in many astrophysical fields, including the search for planetary companions. A new method called "phase closu…
Spatially resolving the inhomogeneous structure of the dynamical atmosphere of Betelgeuse with VLTI/AMBER
K. Ohnaka, K. -H. Hofmann, M. Benisty +8
We present spatially resolved high-spectral resolution K-band observations of the red supergiant Betelgeuse (alpha Ori) using AMBER at the Very Large Telescope Interferometer (VLTI…
System overview of the VLTI Spectro-Imager
L. Jocou, J. P. Berger, F. Malbet +30
The VLTI Spectro Imager project aims to perform imaging with a temporal resolution of 1 night and with a maximum angular resolution of 1 milliarcsecond, making best use of the Very…
Joint Sub-carrier and Power Allocation for Efficient Communication of Cellular UAVs
H. Hellaoui, M. Bagaa, A. Chelli +1
Cellular networks are expected to be the main communication infrastructure to support the expanding applications of Unmanned Aerial Vehicles (UAVs). As these networks are deployed…
VSI: the VLTI spectro-imager
F. Malbet, D. Buscher, G. Weigelt +51
The VLTI Spectro Imager (VSI) was proposed as a second-generation instrument of the Very Large Telescope Interferometer providing the ESO community with spectrally-resolved, near-i…
First AMBER/VLTI observations of hot massive stars
R. G. Petrov, F. Millour, O. Chesneau +45
AMBER is the first near infrared focal instrument of the VLTI. It combines three telescopes and produces spectrally resolved interferometric measures. This paper discusses some pre…
Optimized fringe sensors for the VLTI next generation instruments
N. Blind, O. Absil, J. -B. Lebouquin +2
Context. With the arrival of the next generation of ground-based imaging interferometers combining from 4 to possibly 6 telescopes simultaneously, there is also a strong need for a…
MATISSE, the VLTI mid-infrared imaging spectro-interferometer
B. Lopez, S. Lagarde, R. G. Petrov +150
Context:Optical interferometry is at a key development stage. ESO's VLTI has established a stable, robust infrastructure for long-baseline interferometry for general astronomical o…
SearchCal: a Virtual Observatory tool for searching calibrators in optical long baseline interferometry. I: The bright object case
Daniel Bonneau, J. -M. Clausse, X. Delfosse +6
In long baseline interferometry, the raw fringe contrast must be calibrated to obtain the true visibility and then those observables that can be interpreted in terms of astrophysic…
Estimating the phase in ground-based interferometry: performance comparison between single-mode and multimode schemes
E. Tatulli, N. Blind, J. P. Berger +2
In this paper we compare the performance of multi and single-mode interferometry for the estimation of the phase of the complex visibility. We provide a theoretical description of…
Fiber optic interferometry: Statistics of visibility and closure phase
E. Tatulli, A. Chelli
Interferometric observations with three telescopes or more provide two observables: closure phase information together with visibilities measurements. When using single-mode interf…
Efficient Steering Mechanism for Mobile Network-enabled UAVs
H. Hellaoui, A. Chelli, M. Bagaa +1
HTTP Adaptive Streaming (HAS) is becoming the de-facto video delivery technology over best-effort networks nowadays, thanks to the myriad advantages it brings. However, many studie…
Optical configuration and analysis of the AMBER/VLTI instrument
S. Robbe-Dubois, S. Lagarde, R. G. Petrov +23
This paper describes the design goals and engineering efforts that led to the realization of AMBER (Astronomical Multi BEam combineR) and to the achievement of its present performa…
AMBER/VLTI observations of the B[e] star MWC 300
Y. Wang, G. Weigelt, A. Kreplin +8
Aims. We study the enigmatic B[e] star MWC 300 to investigate its disk and binary with milli-arcsecond-scale angular resolution. Methods. We observed MWC 300 with the VLTI/AMBER in…