Thanks to the Cosmic Web Imager (a spectrographic imager that takes photographs at different wavelengths simultaneously), a team of astronomers from the California Institute of Technology (CalTech) has managed for the first time to take 3D images of the intergalactic medium (IGM) which is equivalent to 3% of the entire universe.
The intergalactic medium is the diffuse gas that connects galaxies throughout the universe , a network of small and large filaments criss-crossing through the vastness of space, whose structure, until now, had been solely the result of speculation. With the Cosmic Web Imager deployed in the 200-inch Hale telescope at the Mount Palomar Observatory (USA), the first three-dimensional images of the intergalactic medium have begun to be obtained.
The "tenuous matter" , as they have called the diffuse gas that makes up the intergalactic medium, is quite difficult to see . The first observed cosmic filaments are in the vicinity of two very bright objects and these filaments affect their dynamics.
The two objects observed were: a quasar labeled QSO 1549 19 and the so-called Lyman alpha bubble in an emerging galaxy cluster known as SSA22. Both objects were chosen by Christopher Martin, creator of the Cosmic Web Imager, for the initial observations and correspond to 2 billion years after the Big Bang .
