Brent Tully
Inst. Astron., Univ. Hawaii (Honolulu, Hawaii, Etats-Unis d'Amérique)
Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris
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| « Cosmicflows-2 » |
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Brent Tully |
| Cosmicflows-2 is a compendium of 8000 galaxy distances. There is dense and accurate coverage locally, with limited information to z=0.1. With distances, radial components of peculiar velocities can be separated from cosmic expansion velocities. In high density environments where non-linear gravitational effects are important, galaxy orbits are reconstructed with numerical action methods. In the linear regime, a Wiener Filter method is used to recover 3D velocities and the density field. Overall, there is a dominant flow toward the Shapley Concentration, at the edge of our data zone, and possibly beyond. We draw particular attention to the basin of attraction that we live in that is within our data zone that we are calling the Laniakea supercluster. Although already containing 10^17 solar masses, Laniakea is ultimately only a part of something even bigger. |
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vendredi 28 février 2014 - 11:00 Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris |
| Page web du séminaire / Seminar's webpage |