African VLBI Network Training Site


Invited Talk: Thursday 30 May - Prof Patrick Charlot

30 May 2019 11:30 - 13:00

Title: Overview of Astrometric VLBI and Celestial 
Reference Frames

Author: Prof Patrick Charlot 
              Astrophysique de Bordeaux
              Université de Bordeaux


More about the author:

PCharlot 240917

Patrick Charlot has worked in the field of geodetic, astrometric and astrophysical VLBI for more than 30 years, originally at Paris Observatory (where he obtained a Ph.D. in 1989) and, since 1998, at the University of Bordeaux in the southwest of France. He also stayed as a postdoc fellow at the Jet Propulsion Laboratory (JPL), USA in 1989-1990.

Patrick pioneered studies of radio source structure from geodetic and astrometric VLBI data, including the effect of such structures on the VLBI observables and the celestial reference frame. Following up on his early work, he introduced the now widely-used structure index, an indicator of source quality, and pushed imaging of the reference frame sources. This led to the Bordeaux VLBI Image Database, which now incorporates more than 6000 images from extragalactic radio sources. Additional contributions are concerned with studies of the Earth’s precession and nutation, the estimation of the link between the dynamical and extragalactic frames, and astrophysics of active galactic nuclei, in particular from VLBI observations.

Patrick chaired the ICRF3 Working Group (2015-2018) who delivered the current celestial reference frame, adopted by the International Astronomical Union (IAU) in August 2018.  has also long been connected with European VLBI, as chair of the European VLBI Network Programme Committee from 2003 to 2008 and, presently, through the project JUMPING JIVE. Patrick is a member of the JIVE council, representing France, and a member of the IVS Directing Board, representing the International Astronomical Union (IAU). His interest also extends to the Gaia space mission for linking the radio and optical frames and understanding the underlying source physics. He is a member of the Data Processing and Analysis Consortium for Gaia. Patrick was Director of the Laboratoire d’Astrophysique de Bordeaux (formerly Bordeaux Observatory) from 2008 to 2015.