I am a member of large international collaborations :

EUCLID space telescope scientist
CLUES numerical simulations
SKA PathFinder Wallaby HI survey
WNSHS Westerbrok Northern Sky HI Survey
Pan-STARRS survey
S4G SPITZER for Galaxies
NRAO National Radio Astronomy Observatory users committee

My goal is to understand the structure and dynamics of the local universe combining observational data and  numerical simulations. My observational program Cosmic Flows is focused on measuring galaxy distances and peculiar velocities. More than 1,000 hours are allocated to this program at GBT (USA), Parkes (Australia). The observed velocity field is then used within the consortium CLUES (Constrained Local UniversE Simulations) as input for numerical cosmological simulations. The observed local universe and the simulated universe are then compared. This synergy of multi-disciplinary fields (from astronomy to computer science) and worldwide (Europe, USA, Russia, Australia, South Africa) uniquely distinguishes my program. This integrated international research effort from observations to simulations is leading to fundamental discoveries of deviations from the expansion of the universe. We find accelerations from voids, and map gravitational attraction on scales from neighboring galaxies to superclusters. We test the law of gravitation, and learn about the dominant components of the universe:  dark matter and dark energy.

The observational program is conducted with the most appropriate radio, optical and space telescopes in the world which for our program are in the USA and Australia. The theoretical analysis is carried out with a latest-generation constrained simulation program developed in Germany and Spain. As the lead of the observational activities I bring to the computer science collaboration a sophisticated understanding of the galaxy catalogs, and as a partner in the simulations I provide the observer partners  and the EUCLID consortium with simulated catalogs and insight of natural phenomena.

 The Extragalactic Distance Database [http://edd.ifa.hawaii.edu]

The material acquired during the course of the Hubble Space Telescope, radio, and optical observing are managed and made available to the community through EDD, the Extragalactic Distance Database [Tully et al. 2009, AJ, 138, 323].  We integrate archived data acquired by others with our own products.  We also gather material relevant to the measurement of galaxy distances with other techniques.  Particular attention is given to Cepheid period-luminosity relation, surface brightness fluctuation, fundamental plane, and supernova type Ia results.  Attention is given to assure that distances determined by different techniques and different observers have consistent scales.

The general public is hungry for public outreach activities and for information. Meanwhile, few European researchers have the training to develop adequate responses to these social and economic needs. I have organized many public events, I visit yearly elementary and high school classes. In 2009 I participated in the production of two DVD's: on the launch of the CERN-LHC and its objectives to uncover the physics of fundamental forces and particles; and on the duality of amateur and professional astronomy.

IPNL
4 rue Enrico Fermi - La Doua
69622 Villeurbanne Cedex, France

h.courtois@ipnl.in2p3.fr
courtois@ifa.hawaii.edu