When I ask the Google AI “Bard” I get the following answer. I have no idea whether the calculation is correct...
Ann wrote: ↑Fri Nov 17, 2023 5:33 am
What I found frustrating about this particular news item is that the Cosmic Vine is that we were told that its redshift is z = 3.44, but we weren't told what distance this redshift corresponds to.
AVAO wrote: ↑Thu Nov 16, 2023 8:04 pm
The 'Cosmic Vine': Astronomers discover a large structure that hosts at least 20 massive galaxies
Phys.org | 2023 Nov 15
An international team of astronomers reports the discovery of a large-scale structure that consists of at least 20 massive galaxies. The structure, dubbed "Cosmic Vine," has a size of about 13 million physical light years. ...
Massive and dense structures of galaxies are perceived as progenitors of galaxy clusters — the most massive gravitationally-bound systems in the universe. Therefore, detecting new structures of this type and investigating them in detail is fundamental for our understanding of galaxy formation and evolution.
Now, a group of astronomers led by Shuowen Jin of the Technical University of Denmark, has detected a new object of this type — a large vine-like structure, hence its name Cosmic Vine. The structure was revealed at a redshift of 3.44, in the Extended Groth Strip (EGS) field observed with JWST. The observations were complemented by data from the Hubble Space Telescope (HST)."
Shuowen Jin et al, Cosmic Vine: A z=3.44 Large-Scale Structure Hosting Massive Quiescent Galaxies, arXiv (2023).
I think I have been told that there is not always an exact correlation between redshift and distance, but even so, I would so much like to know the approximate distance to this proto-cluster.
I was once shown a formula that I could use to calculate distance from redshift, but I refuse to even try, as I am a math idiot.
So, can anyone help me? Chris?
The distance corresponding to a redshift of z = 3.44 depends on the cosmological model used. The most widely accepted cosmological model is the Lambda-CDM model, which assumes that the universe is flat and that its expansion is accelerating due to a cosmological constant. In this model, the distance corresponding to a redshift of z = 3.44 is about 13.5 billion light-years.
The distance to a galaxy with a redshift of z = 3.44 can be calculated using the following formula:
d = c * z / H
d is the distance to the galaxy in light-years
c is the speed of light in a vacuum
z is the redshift of the galaxy
H is the Hubble constant
The Hubble constant is a measure of the expansion rate of the universe. The current value of the Hubble constant is about 67.8 kilometers per second per megaparsec.
Plugging in the values for z and H, we get:
d = 300,000 km/s * 3.44 / 67.8 km/s/Mpc
d = 15,000 Mpc
One megaparsec is about 3.26 million light-years, so 15,000 Mpc is about 48.9 billion light-years. However, we need to take into account that the universe has been expanding since the light from the galaxy was emitted. To do this, we use a factor of (1 + z), which is about 4.44 in this case.
Therefore, the distance to the galaxy with a redshift of z = 3.44 is about 13.5 billion light-years.
... but if it's true, that's pretty far away.