HST ultra deep field and angular diameter

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SUMMARY

The discussion centers on the Hubble Space Telescope's ultra deep field observations and the implications of redshift on the apparent angular size of distant galaxies. Observers note that galaxies at redshifts of approximately 1.65 should exhibit increasing angular sizes according to the L-CDM model, yet the observed sizes appear larger than expected for galaxies with redshifts as high as 7-8. This discrepancy raises questions about the true sizes of these distant galaxies, suggesting they may be much smaller than they appear. The conversation emphasizes the significance of redshift in understanding cosmic structures.

PREREQUISITES
  • Understanding of redshift and its implications in cosmology
  • Familiarity with the L-CDM model of cosmology
  • Knowledge of angular diameter distance in astrophysics
  • Basic principles of observational astronomy using the Hubble Space Telescope
NEXT STEPS
  • Research the relationship between redshift and angular diameter distance in cosmology
  • Study the L-CDM model and its predictions regarding galaxy formation
  • Explore the techniques used in Hubble Space Telescope imaging and data analysis
  • Investigate the characteristics of high-redshift galaxies and their formation theories
USEFUL FOR

Astronomers, astrophysicists, and students interested in cosmology, particularly those studying the formation and characteristics of distant galaxies as observed through the Hubble Space Telescope.

AWA
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Looking at the ultra deep field view from the Hubble as shown here:

http://hyperphysics.phy-astr.gsu.edu/hbase/astro/deepfield.html#c1

Just by observing this picture is not evident the effect in the apparent angular size expected from redshifts z of about 1.65.(According to the L-CDM model the angular size should start increasing from z about 1.6) since we are supposed to be looking to galaxies that reach redshifts as high as a z of 7-8 I guess the smallest objects that are observed with the highest redshifts we actually see with an apparent size much bigger than they really have and therefore they really must be tiny galaxies in reality, or am I missing something here?

Thanks
 
Last edited:
Space news on Phys.org
This is really interesting and it's amazing to think that we can look so far into space and see galaxies that are so far away. It seems like the redshifts of these galaxies would play an important role in our understanding of them, so it's good to know that we can use the Hubble to observe them and get a better idea of what they look like.
 

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