B What is the highest redshift (Z number) a galaxy can have?

[wolram]

Galaxies seem to being found further and further back to the BB, At what epoch is it going to be impossible for galaxies to form?
https://arxiv.org/abs/0912.4263

 

[jedishrfu]

THe wiki article has a topic on the highest redshift that may answer your question:

https://en.wikipedia.org/wiki/Redshift#Highest_redshifts

There's also a list of distant objects:

https://en.wikipedia.org/wiki/List_of_the_most_distant_astronomical_objects

 

[wolram]

Thank you for the reply, as I can make out atoms formed about
Z=20 at the latest, so I expect galaxies to form some time after that.?

 

[kimbyd]

Thank you for the reply, as I can make out atoms formed about
Z=20 at the latest, so I expect galaxies to form some time after that.?

Atoms formed sometime before z=1089 (the redshift of the CMB). Perhaps you meant stars?

The formation of the first stars and galaxies would have been the event which kicked off the process of reionization:
https://en.wikipedia.org/wiki/Reionization

The basic process is that as the first stars formed, they put out a lot of photons that were high enough in energy to ionize the gas that was spread throughout the universe. These stars would have formed in the most dense regions first, forming the first galaxies.

 

[Chronos]

The current tlimit on redshift is believed to be beteen z=22 and z=23. which corresponds to the so-called dark ages which lasted until the universe was about 150,000,000 years old Star formation should theoretically not have begun any earlier than that. It is, however, considered theoretically possible the seeds of what would become supermassive black holes black holes could have fromed before the first stars lit up. Thes JWST could possibly detects these as discussed here; https://arxiv.org/abs/1203.6075, The Formation of the First Massive Black Holes.

 

[wolram]

Thank you for replies.