"The Paris Local Universe Simulations: Dark Matter Sky Maps"
© Guilhem Lavaux
This picture shows the result of a high resolution N-body simulation which has been specifically designed to look like the Local Universe. More precisely it depicts what is the sky of an observer which would be located at the center of our galaxy and look at the entire sky. We use for that a Mollweide projection, which is another way of representing the surface of a full sphere like in geography to represent the surface of the Earth.
The simulation itself is shown through the blue-red colored density field which represents the projection of the 3d density field from our position to a distance of 100 Mpc/h (roughly 300 millions of light years). In addition we represent the true observed galaxies of our Local Universe with small green discs. We clearly see that the green discs and the colored density field track each other. This is a feature of this simulation. This technique will allow to compute complementary observables and cross-check their predictions to actual observations (e.g. X-ray observations, Microwave Background sky).
The darker areas depict the sky limit of the catalog used to constrain and build the simulation. In the plane of the sphere, we see that no object has been observed. Indeed this plane contains our galaxy whose emission and absorption properties hinder the detection and characterization of galaxies lying behind.