Ancient 'ring of fire' galaxy found glaring at Earth across space and time

I note from the nature astronomy link provided in this article two points. From the abstract "Our discovery offers a unique pathway for studying density waves in young galaxies, as well as constraining the cosmic evolution of spiral disks and galaxy groups. The ring galaxy (ID 5519, hereafter R5519) was..."

Density waves are required to regenerate spiral arms in galaxies, spiral arms have limited lifetimes compared to the age of the universe in the BB model and galaxy ages assigned (perhaps 100-300 million years max). If not regenerated we live in a unique period to see spiral arms today. The other point here, DM is critical to the model calculations and distance interpretation too.

"Methods Throughout we adopt a Λ cold dark matter cosmology, where is Λ the cosmological constant, with ΩM = 0.307, ΩΛ = 0.693 and H0 = 67.7 km s−1 Mpc−1, consistent with the Planck measurements31 and the cosmological parameters used in EAGLE simulations13. At the redshift of z = 2.19, the look-back time is 10.8 Gyr and 1″ corresponds to a physical scale of 8.49 kpc. All magnitudes are in AB units32, unless otherwise specified."

The redshift for R5519 is z=2.19.