Séminaire / Seminar GReCO |
| « Study of the supermassive blackhole at the center of the Galaxy with GRAVITY » |
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Guy Perrin |
| The galactic center houses an object whose mass is estimated about 4 million solar masses. This object, surrounded by a complex gazeous and dusty region rich of stars, has never been resolved. There is strong hints that it is a supermassive blackhole as expected for any central object of galaxies. No method has allowed yet to study these blackholes in a direct and recurring manner. The ambition of GRAVITY is to get direct informations on the central object at a scale comparable to that of the horizon. For this, GRAVITY combines the four large 8.20 m telescopes of the European Very Large Telescope in Chile in interferometric mode. This technique gives access to the angular resolution and to the astrometric precision of a 140-meter telescope. The project started in 2005 and first light was obtained at the end of 2015 with the smaller 1.80 m telescopes. It is since being tested every month at the VLT. First observations of the environment of Sgr A* were taken in spring 2016. First results are expected for the end of 2016 or in 2017. I will present the observation projects with GRAVITY as well as the first results, in particular the prospects for first relativistic effects on the closest star to the blackhole yet known, IRS2. |
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lundi 12 septembre 2016 - 10:30 Salle des séminaires Évry Schatzman Institut d'Astrophysique de Paris |
| Pages web du séminaire / Seminar's webpage |