James Webb Space Telescope discovers candis for most distant galaxies yet

[Admin]

Astronomers have spotted two candis for the most distant galaxies ever, thanks to the power of a massive gravitational lens.

James Webb Space Telescope discovers candis for most distant galaxies yet : Read more

 

[rod]

"Astronomers led by Rohan Naidu of the Harvard–Smithsonian Center for Astrophysics discovered the two candidate galaxies, called GLASS-z11 and GLASS-z13, in the first batch of data from GLASS. The galaxies' designations come from the fact that astronomers have measured their "redshifts" to be 11 and 13 respectively."

Impressive here. The paper I read on this find is Two Remarkably Luminous Galaxy Candidates at z ≈ 11 − 13 Revealed by JWST, 2207.09434.pdf (arxiv.org)

I note 12-pages. "6. SUMMARY & OUTLOOK This paper presented a search for luminous z > 10 galaxies across the two JWST Early Release Science programs in extragalactic fields. We find the following – • We identify two particularly luminous sources in the GLASS ERS program. These sources, GL-z11 and GL-z13, have continuum magnitudes of ∼ 27 at 2 µm and display dramatic > 2 mag breaks in their SEDs that are best fit as Lyman breaks occurring at redshifts of z ≈ 11 and z ≈ 13 respectively. [Fig. 1, Fig. 2, §4.1] • SED modeling of these sources shows they have properties (e.g., β slopes, specific star-formation rates) expected of z > 10 galaxies. These systems are a billion solar mass galaxies, having built up their mass only < 300 − 400 Myrs after the Big Bang. [Table 3, §4.3...If these candidates are confirmed spectroscopically, and indeed two z ≈ 11 − 13 candidates lie awaiting discovery in every ∼50 arcmin2 extragalactic field, it is clear that JWST will prove highly successful in pushing the cosmic frontier all the way to the brink of the Big Bang."

[My note. The comment near the end of the paper indicates that GL-z13 remains to be spectroscopically determined redshift, presently Lyman break method. The phys.org report is out too, Webb telescope may have already found most distant known galaxy, https://phys.org/news/2022-07-webb-telescope-distant-galaxy.html, 21-July-2022, "Though GLASS-z13 existed in the earliest era of the universe, its exact age remains unknown as it could have formed anytime within the first 300 million years."

My note, using cosmology calculators like https://lambda.gsfc.nasa.gov/toolbox/calculators.html or https://www.kempner.net/cosmic.php and z = 13, you will get age at redshift near 300 Myr old after the BB event. The comoving radial distance is more than 33 Gly distance so 4D space expanding faster than c velocity is required to accept the interpretation and age calculation too.

 

[Unclear Engineer]

As soon as there was "mass" in the universe, I would expect it to start to clump in places due to gravitational collapse of non-homogeneities, even if it was not yet "atoms" or "plasma".

So, by apparent definition, having "galaxies" seems to be a matter of having "stars" that provide us with light to see. But, galaxies are made up of a lot more than light emitting stars.

These days, galaxies have "dust" that is comprised of heavier than helium atoms that are assumed to have been created by many generations of very evolved stars that fused hydrogen and helium into atoms of "metals" - some in the process of stellar fusion and some in the process of stellar "deaths" by gravitational collapse and supernova explosions when the central fusion processes were exhausted of suitable lighter element fuels. However, there appears to be more dust in our galaxy than we can explain with our current theory of star formation following the Big Bang - (can't find link that says this right now).

So, it seems to me that what we want from Webb Telescope is more info about what is in those early galaxies. Do they contain dust? Do they already have central black holes? Does their rotation seem consistent with our current beliefs about the existence and distribution of "dark matter"?

I do wonder about the concept that the cosmic microwave background was emitted (as light) 13.42 billion years ago, which is only 0.38 billion (or 380 million) years after the Big Bang is theorized to have occurred. If so, then how are we seeing starlight that was emitted only 300 million years after the BB, which should have been absorbed instead of getting through to us, now? Is this just a matter of uncertainties in the two estimates overlapping? Or, will Webb soon show us even "older" light that causes an even more obvious conflict with the current time line? (And, will theorists have to insert yet another unconstrained parameter to "fix" the Theory?)