Astronomers created largest ever map of the universe, looking back 13.8bn years
Staff Writer |
Sloan Digital Sky Survey (SDSS) have created the best known map of the large scale structure of the universe, based on the positions of quasars.
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Quasars are glowing rings of matter and energy around supermassive black holes, and are incredibly bright. This allows scientists to use them as markers, as the brightness of the quasars allow them to be clearly observed even from incredible distances.
Ashley Ross of the Ohio State University, the co-leader of the study said “Because quasars are so bright, we can see them all the way across the Universe. That makes them the ideal objects to use to make the biggest map yet.â€
Gongbo Zhao from the National Astronomical Observatories of Chinese Academy of Sciences, the other co-leader of the study said, “These quasars are so far away that their light left them when the Universe was between three and seven billion years old, long before the Earth even existed.â€
On the left of the map is the Earth, and towards the right, the map goes backwards in time.
At the very edge of the map is the cosmic background radiation, a light signature from the big bang. The red dots are the quasars, and the nearby galaxies are shown as yellow dots.
The black band between the quasars and the cosmic background radiation is from a period of the history of the universe known as the “dark agesâ€. This was a time before the formation of most galaxies, stars and star systems.
In 2016, the hundreds of scientists from the SDSS collaborated to make the largest 3D map of the universe.
Individual galaxies were measured over a decade, and even then only a quarter of the sky was mapped in three dimensions. The map allowed scientists to measure the impact of dark energy on universal expansion.
Rita Tojeiro of the University of St. Andrews had explained the map, “we see a dramatic connection between the sound wave imprints seen in the cosmic microwave background 400,000 years after the Big Bang to the clustering of galaxies 7-12 billion years later.
“The ability to observe a single well-modeled physical effect from recombination until today is a great boon for cosmology.†■