Ticker

6/recent/ticker-posts

Ad Code

Responsive Advertisement

Webb reveals more record-breaking galaxies

skay juillet 28, 2022
Webb: Hundreds of small-to-tiny oblong glowing objects (galaxies) in a dark sky.
The James Webb Space Telescope captured a tiny slice of the vast universe for its 1st image. What you’re seeing is approximately the size of a grain of sand held at arm’s length. Teams of scientists are finding record-breaking distant galaxies, pushing back the boundaries of what we know. Image via Webb.

Webb reveals more record-breaking galaxies

Just last week, a group of scientists announced they’d found the oldest galaxy yet in James Webb Space Telescope images. This galaxy, GLASSz-13, existed when the universe was just 300 million years old. Since then, teams of astronomers have been pushing the goalposts further and further. On arXiv, a digital platform where scientists share their moderated discoveries that are sometimes still awaiting peer review, scientists are posting a slew of studies where they’ve spotted galaxies in Webb images that may be even younger.

Significantly, the record-breaking galaxies are oldest in that we are looking far back in time to spot them, and also the youngest in that the universe was in its infancy then and galaxies were just being born. In addition, they’re also the farthest or most distant galaxies we’ve seen. Indeed, these superlatives are well earned.

Expansion of space and redshift

Furthermore, the light from these distant galaxies has been traveling for billions of years. The expansion of space stretches out the light’s wavelength, shifting everything toward the red end of the spectrum. Accordingly, astronomers measure the redshift, using the letter z to represent the redshift amount. For example, the bigger the z value, the more redshifted the object is, and the farther away from us it is in the universe. With this in mind, farther away also means farther back in time, or when the universe was younger.

For example, a redshift of 1 means that the light we measure has travelled 7.7 billion years and that the object (for example a galaxy) sending out the light is located 10.1 billion light years away from us. But, shouldn’t these values be the same? In a word, no, because the universe kept expanding as the light traveled so the object is now much farther away than it was then it started sending out the light we now measure.

New papers

A sample of the new papers include one published on July 25 revealing redshifts of 8-15, another one published July 25 with candidates with a redshift of 16, and one published on July 23 announcing a batch of candidate galaxies with redshifts of 11-20.

To be sure, these papers still have to be peer reviewed. However, some of the candidate galaxies, if confirmed, would have existed when the universe was less than 200 million years old.

Astronomers take to Twitter with explanations

Also, because the papers are still awaiting peer review, the astronomers’ associated organizations have not yet issued press releases. So, as a result, astronomers and others have taken to Twitter to start sharing and explaining their discoveries.

A closer look at one of the most distant galaxies seen by Webb

The Cosmic Evolution Early Release Science (CEERS) survey is one of the groups that found a candidate galaxy that may have existed when the universe was less than 300 million years old. Accordingly, they published their study on arXiv on July 25, 2022. They’ve nicknamed their candidate “Maisie’s Galaxy.” Incredibly, it would have existed less than 290 million years after the Big Bang.

Steve Finkelstein of the University of Texas at Austin was an author on the paper and shared a long tweet thread on their discovery, which you can read in its entirety here.

In the images above, the image on the left shows the effect of redshift on the light from the galaxy. Conversely, the image on the right (blue) shows its “true” color, the color the galaxy would have without redshift.

One unexpected fact about Maisie’s Galaxy, surprisingly, is that it’s modestly large. Basically, because galaxies were just beginning to form, scientists didn’t expect large galaxies to have formed yet this far back in time.

Rebecca Larson, another author of the paper, shared this tweet of the Webb images they’ve been combing through.

A humorous look at new galaxies

Astronomers, science writers and enthusiasts took to Twitter to express their awe with the flurry of new discoveries of the “oldest,” “youngest” and “most distant” galaxies.

Bottom line: Scientists are finding galaxies in the James Webb Space Telescope images that would break barriers on the farthest galaxies ever seen. Some may have existed when the universe was less than 200 million years old.

Sources:

A Long Time Ago in a Galaxy Far, Far Away: A Candidate z ~ 14 Galaxy in Early JWST CEERS Imaging

First Batch of Candidate Galaxies at Redshifts 11 to 20 Revealed by the James Webb Space Telescope Early Release Observations

Revealing Galaxy Candidates out to z ~ 16 with JWST Observations of the Lensing Cluster SMACS0723

The evolution of the galaxy UV luminosity function at redshifts z ~ 8-15 from deep JWST and ground-based near-infrared imaging

The post Webb reveals more record-breaking galaxies first appeared on EarthSky.

Enregistrer un commentaire

0 Commentaires

Emoji
(y)
:)
:(
hihi
:-)
:D
=D
:-d
;(
;-(
@-)
:P
:o
:>)
(o)
:p
(p)
:-s
(m)
8-)
:-t
:-b
b-(
:-#
=p~
x-)
(k)