At 10:30 am Eastern on Tuesday, July 12, we are going to get to see the first multi-color, fully processed science images from the JWST. We will be hosting a watch party for the event on Twitch.tv/CosmoQuestX. But in these last pre-JWST days, we continue to celebrate the science folks figured out how to do without the JWST using all manner of creativity. Our favorite method remains gravitational lensing: a technique that allows astronomers to study the most distant galaxies using light that is gravitationally bent our way by massive galaxy clusters that act like magnifying glasses – very, very imperfect magnifying glasses.

In 2012, a tiny galaxy was found magnified by the gravity of the cluster MACS J1149+223. With its light shining toward us from just 500 million years after the Big Bang, this newly imaged system showed us stars that likely started forming just 200 million years after the Big Bang.

Now, follow-up observations using the Atacama Large Millimeter/submillimeter Array (ALMA) and published in The Astrophysical Journal by a team led by Tsuyoshi Tokuoka, show that this little system – cataloged as MACS1149-JD1 – has a mass of about 1 million Suns, is 3,000 light-years across and is rotating about 50 kilometers per second. This small system is basically doing a small spin and showing us just how galaxies form, grow, and spin up over the eons.

Like so many other research teams, this one points out that JWST will be able to observe just how typical this galaxy is and fill in the missing pieces in our understanding as it directly observes – no gravitational lensing required – the first galaxies forming.

More Information

NAOJ press release

“Possible Systematic Rotation in the Mature Stellar Population of a z = 9.1 Galaxy,” Tsuyoshi Tokuoka et al., 2022 July 1, The Astrophysical Journal Letters