After all, the Universe has roughly two billion (a million million) galaxies, that is, ten times more than thought up to now, concludes a study by an international team of astronomers published this Thursday. In recent years, astronomers thought the Universe contained between 100 billion and 200 billion galaxies.
The team of Christopher Conselice, University of Nottingham (Uk), worked with the data obtained by the Hubble space telescope, developed by NASA with the European Space Agency, and by other telescopes. With this information, scientists have built carefully images in 3D and moved the number of galaxies present in different moments of the history of the Universe. The farther away the galaxies are, the weaker is the light they emit and that comes to us. The telescopes that we use today make it possible to study only about 10% of the galaxies.
"It’s amazing to think that 90% of the galaxies in the cosmos have yet to be studied," says Christopher Conselice. "Who knows what we will discover when we begin to study these galaxies using the new generation of telescopes", wonders the scientist in a press release published after the publication of the study in the journal Astrophysical Journal.
For the calculations, the team of astronomers used statistical methods and has drawn on the knowledge that we have of the Universe closest to predict what will happen further. "The study is very interesting, although we have some reservations about the precise number of galaxies," says François Hammer, an astronomer of the Observatory of Paris and specialist in the formation of galaxies, in statements to the agency AFP.
"Christopher Conselice did the best we could do at this time. But the result may not be considered the final word," said the astrophysicist. "It is a work that can not be confirmed until we have telescopes and giant that allow us to see much better in these distant regions," said Francois Hammer.
The Telescope the European Extremely Large E-ELT (European Extremely Large Telescope) is about to start being built in Chile by the European Southern Observatory (ESO, an intergovernmental organisation of european that belongs to Portugal). Your primary mirror will have a diameter of 39 metres. The telescope is expected to start operating "in 2024/2025" needed to François Hammer, scientific coordinator of your spectrograph, multi-object (MOS). This instrument will allow to observe extremely distant galaxies.
The United States also intend to build in Hawaii, the Thirty Meter Telescope (TMT), which will have a power targeted to 30 meters.
The study now published reinforces a scenario that is "in fashion" and argues that the galaxies are formed when merge with each other, notes François Hammer. "In the beginning, there are many galaxies small, and then merge, becoming larger and larger," said the scientist, adding: "Within 3000 to 4000 million years, our galaxy, the Milky way, will meet with Andromeda and form a another galaxy."