Gamma Ray Bubble at the center of our galaxy seen by Fermi Telescope How could we measure high energy photons, whithout measuring them ?
I can't understand how we can "see" those Gamma Ray Bubbles if they are not reaching here
In this graph from Nasa you can see those "bubbles" are not reaching solar system:

Then how could be measure that Gamma Ray without the Gamma Rays
Thanks for any answer!
 A: Concerning the 8-shaped bubbles around the galaxy, see

http://motls.blogspot.com/2010/11/fermi-milky-way-cutting-x-ray-infinity.html
http://arxiv.org/abs/arXiv:1005.5480

They're not pictures of photons - X-rays themselves. The infinity symbol is a picture of X-ray sources: we are observing the X-rays that came from those sources here. Note that the whole structure is smaller than 100,000 light years or so - very tiny when compared to the cosmological distances. So if the 8-shaped sources were created 10 million years ago, the time needed for the photons to get here is negligible. They're here "immediately".
It's hard to measure the distance from which an X-ray is approaching us. However, you should understand that the Sun and the Earth are not in the middle of the Milky Way. They're not in the middle of the 8-shaped figure. We're looking at the situation from the "side" (the Solar System is somewhere between the center and the visible edge of our Galaxy) so we literally see something that is 8-shaped in the skies. Assuming that the distribution of the sources is rotationally symmetric - with respect to the Milky Way's axis - one can actually reconstruct the shape of the sources in 3D from the 2D picture we see (because the 3D picture only depends on 2 dimensions, because of the axial symmetry).
