A5044100084- Geophysics and Gravity Measurements
- GNSS positioning and interference
- Astronomical Observations and Instrumentation
- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Radio Astronomy Observations and Technology
- Ionosphere and magnetosphere dynamics
- Inertial Sensor and Navigation
- Statistical and numerical algorithms
- Geomagnetism and Paleomagnetism Studies
- Solar and Space Plasma Dynamics
- Scientific Research and Discoveries
- Stellar, planetary, and galactic studies
- Advanced Frequency and Time Standards
- Atmospheric Ozone and Climate
- Calibration and Measurement Techniques
- Spacecraft Dynamics and Control
- Regional Economic and Spatial Analysis
- Target Tracking and Data Fusion in Sensor Networks
- Underwater Acoustics Research
- Geological and Geophysical Studies
- Time Series Analysis and Forecasting
Laboratoire d'Astrophysique de Bordeaux
2018-2021
Université de Bordeaux
2018-2019
Centre National de la Recherche Scientifique
2014-2019
Systèmes de Référence Temps-Espace
2013-2018
Sorbonne Université
2015-2018
Université Paris Sciences et Lettres
2016-2018
Observatoire de Paris
2014-2015
Context. From an astrometric point of view, quasars constitute quasi-ideal reference objects in the celestial sphere, with a priori absence proper motion. Since second release Large Quasar Astrometric Catalog (LQAC), large number have been discovered, particular upcoming new SDSS catalog.
Geophysical parameters of the deep Earth's interior can be evaluated through resonance effects associated with core and inner-core wobbles on forced nutations figure axis, as observed by very long baseline interferometry (VLBI), or diurnal tidal waves, retrieved from time-varying surface gravity recorded superconducting gravimeters (SGs). In this paper, we inverse for rotational mode both techniques to retrieve geophysical Earth. We analyse data 15 SG stations VLBI delays accumulated over...
Context. In addition to their great astrophysical interest, quasars represent quasi-ideal reference objects in the celestial sphere with, a priori, lack of significant proper motion. Since fourth release Large Quasar Astrometric Catalogue (LQAC-4), large number have been discovered, particular those coming from DR14Q SDSS. With advent Gaia Data Release 2 (DR2), it is now also possible fold extremely accurate quasar positions. Aims. Following same procedure as previous releases LQAC, our aim...
Context. From an astrometric point of view, quasars constitute the best and almost ideal reference objects in celestial sphere, with a priori no significant proper motion. Since third release Large Quasar Astrometric Catalogue (LQAC-3), large number have been discovered, particular those coming from DR12Q SDSS. Moreover, for cross-matched objects, we taken advantage very accurate determinations identified within recent Gaia DR1 catalogue. Aims. Following same procedure as three previous...
Aims . We investigate the composition of noise in coordinate time series several hundreds extragalactic radio sources monitored by geodetic VLBI program since 1979. The type is identified at all available timescales longer than one year, following observational history source. Methods computed Allan standard deviation and developed a Monte Carlo test to evaluate influence irregular sampling error on data onto identification. classified into three categories depending their taking account...
Context. Thanks to huge surveys, such as the Sloan Digital Sky Survey (SDSS), last decade has shown a dramatic increase in number of known quasars. In second release general compiled catalogue Large Quasar Astrometric Catalogue (LQAC), 187 504 objects are recorded.
Context. Geodetic very long baseline interferometry (VLBI) has been used to observe extragalactic radio sources for more than 40 yr. The absolute source positions derived from the VLBI measurements serve as a basis define International Celestial Reference Frame (ICRF). Despite being located at cosmological distances, an increasing number of these are found show position instabilities, revealed by accumulation data over years. Aims. We investigate how characterize astrometric variations,...
Modeling trajectories of radio components ejected by the nucleus 4C31.61 (2201+315) and observed very long baseline interferometry (VLBI) in frame MOJAVE survey suggests that they are from three different origins possibly host supermassive black holes. These correspond to stationary components, one which is VLBI core. Most mass associated with a binary hole system whose separation ≈0.3 milliarc second, is, distance ≈1.3 parsec ratio ≈2. In contrast, respect third ≈1/100. The lie within 0.6...
Abstract Thanks to their point-like structure and lack of significant proper motion, quasars represent the ideal objects for modeling quasi-inertial directions in space. For that reason present primary conventional reference frame, ICRF-2, is constructed from set celestial coordinates a sample extragalactic objects, whose very large majority are quasars. Thus any newly discovered quasar must be considered as potential future astrometric marker. Therefore compiling all recorded at given epoch...