Big Bang afterglow fails intergalactic shadow test

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    Big bang Shadow Test
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SUMMARY

The discussion centers on the failure of the cosmic microwave background radiation (CMBR) to show expected shadows from galaxies, as only 1 out of 4 galaxy clusters cast shadows. The WMAP Y3 data has largely resolved this anomaly, providing high-resolution all-sky maps of the CMB. The research by Niayesh Afshordi highlights the thermal Sunyaev-Zel'dovich effect, which causes galaxy clusters to appear as small dips in the CMB. The conclusions drawn depend significantly on the assumed density profile of the intracluster medium (ICM), and there are calls for further analysis with Planck data.

PREREQUISITES
  • Understanding of cosmic microwave background radiation (CMBR)
  • Familiarity with the thermal Sunyaev-Zel'dovich effect
  • Knowledge of galaxy cluster dynamics and intracluster medium (ICM)
  • Experience with WMAP (Wilkinson Microwave Anisotropy Probe) data analysis
NEXT STEPS
  • Research the implications of WMAP Y3 data on cosmic microwave background studies
  • Explore the thermal Sunyaev-Zel'dovich effect in detail
  • Study the density profiles of intracluster mediums in cosmology
  • Investigate upcoming Planck satellite data and its potential impact on CMBR analysis
USEFUL FOR

Astronomers, astrophysicists, and researchers focused on cosmic microwave background studies, galaxy cluster dynamics, and the thermal Sunyaev-Zel'dovich effect will benefit from this discussion.

heusdens
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News article on Science daily.
If the cosmic microwave background radiation was a remnant of the big bang fireball, galaxies should cast shadow on this CMBR.
But this test seems to fail, as only 1 out of 4 galaxie clusters cast shadows.

http://www.sciencedaily.com/releases/2006/09/060905104549.htm
 
Space news on Phys.org
WMAP Y3 data has largely resolved this apparent anomaly - e.g.,

http://arxiv.org/abs/astro-ph/0608503
Intracluster Medium through three years of WMAP
Authors: Niayesh Afshordi (Harvard College Observatory)

Wilkinson Microwave Anisotropy Probe (WMAP) has provided us with the yet highest resolution all-sky maps of the Cosmic Microwave Background. As a result of thermal Sunyaev-Zel'dovich effect, clusters of galaxies are imprinted as tiny, poorly resolved dips on top of primary CMB anisotropies in these maps. Here, I describe different efforts to extract the physics of Intracluster Medium (ICM) from the sea of primary CMB, through combining WMAP with low-redshift galaxy or X-ray cluster surveys. This finally culminates at a mean (universal) ICM pressure profile, which is for the first time directly constrained from WMAP 3yr maps, and leads to interesting constraints on the ICM baryonic budget.
 
It seams to me that the conclusions depend strongly on the assumed density profile for the intracluster medium.
 
Absolutely, and this is true of any cosmological conjecture. My issue with the 'shadows' conjecture is the weak treatment of potential CMB scattering effects.
 
Not Yet! Wait for Planck data!

Yesterday 01:43 AM
Chronos WMAP Y3 data has largely resolved this apparent anomaly - e.g.,
http://arxiv.org/abs/astro-ph/0608503
Intracluster Medium through three years of WMAP
Authors: Niayesh Afshordi (Harvard College Observatory)

Not Yet! Wait for Planck data!
If CMB has local origin, there is still the shadowing effect, because there are CMB coming from both local origin of the places near Earth and the local origin of far away places from the earth. But the shadowing effects are imprinted as tiny, poorly resolved dips on top of primary CMB anisotropies in these maps. The BB remnants interpretation would present as large, easily resolved dips on top of primary CMB anisotropies in these maps!
 

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