Galaxies captured in a fraction of the time!

Where the Hubble Space Telescope required an exposure time of more than eleven days to create the “extremely deep field” masterpiece, the James Webb Telescope needed less than a day to paint the same galaxies onto the black canvas.

On October 11, 2022, the James Webb Telescope was instructed to spend 20 hours observing a patch of sky in the constellation The Furnace previously imaged by Hubble 16 years ago. The result was amazing. It took the space telescope less than 10% of Hubble’s exposure time to get the same result.

Webb’s Ultra Deep Field shows distant galaxies that existed when the universe was only 800 million years old. These galaxies are barely visible: they are faint red dots on a grainy black background. The larger foreground galaxies are relatively close when the universe was about a billion years younger than it is now.

We even see hot ionized gas in galaxies. These are the places where stars are born, says Professor Michael Maceda of the University of Wisconsin-Madison. “This information is very important because we still don’t know exactly how galaxies became the way they are today. An exposure time of less than 24 hours isn’t a long time, but in this relatively short time we’ve got a better understanding of how galaxies grew at this particular point.” [reïonisatie, red.] Universe.”

When the universe was very young, there was only neutral hydrogen gas. But the reionization process changed that. A few hundred million years after the Big Bang, stars, galaxies and supermassive black holes were born. Astronomers still do not fully understand where the huge amount of energy needed for this came from.