Epoch of Reionization Archives

January 14, 2022January 14, 2022 by Evan Gough

Nancy Grace Roman Telescope Will do its Own, Wide-Angle Version of the Hubble Deep Field

This synthetic image visualizes what a Roman ultra-deep field could look like. The 18 squares at the top of this image outline the area Roman can see in a single observation, known as its footprint. The inset at the lower-right zooms into one of the squares of Roman's footprint, and the inset at the lower-left zooms in even further. The image, which contains more than 10 million galaxies, was constructed from a simulation that produced a realistic distribution of the galaxies in the universe. Image Credit: Nicole Drakos, Bruno Villasenor, Brant Robertson, Ryan Hausen, Mark Dickinson, Henry Ferguson, Steven Furlanetto, Jenny Greene, Piero Madau, Alice Shapley, Daniel Stark, Risa Wechsler

Remember the Hubble Space Telescope’s Deep Field and Ultra-Deep Field images?

Those images showed everyone that what appears to be a tiny, empty part of the sky contains thousands of galaxies, some dating back to the Universe’s early days. Each of those galaxies can have hundreds of billions of stars. These early galaxies formed only a few hundred million years after the Big Bang. The images inspired awe in the human minds that took the time to understand them. And they’re part of history now.

The upcoming Nancy Grace Roman Space Telescope (NGRST) will capture its own version of those historical images but in wide-angle. To whet our appetites for the NGRST’s image, a group of astrophysicists have created a simulation to show us what it’ll look like.

June 17, 2020June 17, 2020 by Matt Williams

Searching for the End of the Universe’s “Dark Age”

A ‘radio colour’ view of the sky above the Murchison Widefield Array radio telescope, part of the International Centre for Radio Astronomy Research (ICRAC). Credit: Radio image by Natasha Hurley-Walker (ICRAR/Curtin) and the GLEAM Team. MWA tile and landscape Credit: ICRAR/Dr John Goldsmith/Celestial Visions

According to the most widely accepted cosmological theories, the first stars in the Universe formed a few hundred million years after the Big Bang. Unfortunately, astronomers have been unable to “see” them since their emergence coincided during the cosmological period known as the “Dark Ages.” During this period, which ended about 13 billion years ago, clouds of gas filled the Universe that obscured visible and infrared light.

However, astronomers have learned that light from this era can be detected as faint radio signals. It’s for this reason that radio telescopes like the Murchison Widefield Array (MWA) were built. Using data obtained by this array last year, an international team of researchers is scouring the most precise radio data to date from the early Universe in an attempt to see exactly when the cosmic “Dark Ages” ended.

April 4, 2020April 4, 2020 by Paul M. Sutter

Astronomers are hoping to see the very first stars and galaxies in the Universe

The epoch of reionization was when light from the first stars could travel through the early Universe. At this time, galaxies began assembling, as did black holes. The young galaxy JADES-GS-z7-01-QU went through a star burst phase during this time, and then stopped forming stars. Credit: Paul Geil & Simon Mutch/The University of Melbourne

Sometimes it’s easy being an astronomer. When your celestial target is something simple and bright, the game can be pretty straightforward: point your telescope at the thing and just wait for all the juicy photons to pour on in.

But sometimes being an astronomer is tough, like when you’re trying to study the first stars to appear in the universe. They’re much too far away and too faint to see directly with telescopes (even the much-hyped James Webb Space Telescope will only be able to see the first galaxies, an accumulation of light from hundreds of billions of stars). To date, we don’t have any observations of the first stars, which is a major bummer.

November 28, 2019November 28, 2019 by Evan Gough

Astronomers Are About to Detect the Light from the Very First Stars in the Universe

The Murchison Widefield Array radio telescope in remote Western Australia. Brown University.

A team of scientists working with the Murchison Widefield Array (WMA) radio telescope are trying to find the signal from the Universe’s first stars. Those first stars formed after the Universe’s Dark Ages. To find their first light, the researchers are looking for the signal from neutral hydrogen, the gas that dominated the Universe after the Dark Ages.