The impossible early galaxy formation

In summary, the authors of arXiv:1506.01377 discuss the Impossibly Early Galaxy Problem, which refers to the lack of evidence for the expected transition of massive galaxies at redshifts of 4-8. While current theories predict this transition, recent observations from high redshift galaxy surveys suggest that it may have occurred too early. The authors consider possible explanations for this discrepancy, including uncertainties in stellar synthesis models and alternative galaxy formation scenarios. However, there remains a significant tension between observation and theory, indicating the need for further study. Ultimately, the age of the universe is not the main focus of this issue.
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wolram
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Is there general consensus that the universe is to young?
arXiv:1506.01377 [pdf, ps, other]
The Impossibly Early Galaxy Problem
Charles L. Steinhardt, Peter Capak, Dan Masters, Josh S. Speagle
Comments: 7 pages, submitted
Subjects: Astrophysics of Galaxies (astro-ph.GA)

The current hierarchical merging paradigm and $\Lambda$CDM predict that the $z \sim 4-8$ universe should be a time in which the most massive galaxies are transitioning from their initial halo assembly to the later baryonic evolution seen in star-forming galaxies and quasars. However, no evidence of this transition has been found in many high redshift galaxy surveys including CFHTLS, CANDELS and SPLASH, the first studies to probe the high-mass end at these redshifts. Indeed, if halo mass to stellar mass ratios estimated at lower-redshift continue to $z \sim 6-8$, CANDELS and SPLASH report several orders of magnitude more $M \sim 10^{12-13} M_\odot$ halos than are possible to have formed by those redshifts, implying these massive galaxies formed impossibly early. We consider various systematics in the stellar synthesis models used to estimate physical parameters and possible galaxy formation scenarios in an effort to reconcile observation with theory. Although known uncertainties can greatly reduce the disparity between recent observations and cold dark matter merger simulations, even taking the most conservative view of the observations, there remains considerable tension with current theory.
 
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wolram said:
Is there general consensus that the universe is too young?
arXiv:1506.01377 [pdf, ps, other]
The Impossibly Early Galaxy Problem
Charles L. Steinhardt, Peter Capak, Dan Masters, Josh S. Speagle
...
I don't think the age of the universe is at issue here, Wooly.
It is about astronomer's models of star formation, and galaxy formation. The authors, at the end with their conclusions, propose 3 possible explanations for what they see and they all have to do with modeling how structure formation works better--so that it can happen somewhat earlier.
 
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FAQ: The impossible early galaxy formation

What is "The impossible early galaxy formation"?

"The impossible early galaxy formation" refers to the phenomenon of galaxies forming much earlier in the history of the universe than was previously thought possible. This challenges our current understanding of how galaxies form and evolve.

What evidence supports the idea of "The impossible early galaxy formation"?

Observations of distant galaxies using powerful telescopes, such as the Hubble Space Telescope, have shown that galaxies existed as early as 400 million years after the Big Bang. This is much earlier than the predicted time frame for galaxy formation based on current models.

What are the implications of "The impossible early galaxy formation"?

If confirmed, "The impossible early galaxy formation" would require a significant revision of our current understanding of the universe's evolution. It could also have implications for theories about the formation of stars and planets, as well as the origin of dark matter and dark energy.

What are some proposed explanations for "The impossible early galaxy formation"?

Some scientists believe that the early universe may have had more powerful sources of energy, such as supermassive black holes or supernovae explosions, that could have triggered the formation of galaxies at a faster rate. Others suggest that our current understanding of the universe's expansion may be incorrect, leading to an underestimation of the time frame for galaxy formation.

How does "The impossible early galaxy formation" impact future research in astronomy?

"The impossible early galaxy formation" has sparked intense interest and debate among scientists, leading to new theories and hypotheses about the early universe. It also highlights the need for further research and observations to better understand this phenomenon and its implications for our understanding of the universe.

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