Big Bang afterglow fails intergalactic shadow test

In summary: The BB remnants interpretation would present as large, easily resolved dips on top of primary CMB anisotropies in these maps.
  • #1
1,738
0
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
  • #3
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.
 
  • #4
It seams to me that the conclusions depend strongly on the assumed density profile for the intracluster medium.
 
  • #5
Absolutely, and this is true of any cosmological conjecture. My issue with the 'shadows' conjecture is the weak treatment of potential CMB scattering effects.
 
  • #6
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!
 

1. What is "Big Bang afterglow" and how does it relate to the intergalactic shadow test?

"Big Bang afterglow" refers to the cosmic microwave background (CMB) radiation, which is leftover thermal energy from the early stages of the universe. The intergalactic shadow test is a method used to study the CMB and look for any distortions or shadows caused by intervening galaxies or clusters of galaxies.

2. What is the significance of the intergalactic shadow test?

The intergalactic shadow test is significant because it allows us to study the CMB and gather information about the structure and evolution of the universe. By looking for shadows or distortions in the CMB, we can learn about the distribution of matter and energy in the universe.

3. What does it mean for the intergalactic shadow test to "fail"?

A "failed" intergalactic shadow test means that no significant distortions or shadows were found in the CMB. This can be interpreted as evidence that the universe is more homogeneous and isotropic on a large scale, which supports the idea of the Big Bang theory.

4. Are there any alternative explanations for the failure of the intergalactic shadow test?

Yes, there are some alternative explanations for the failure of the intergalactic shadow test. One possibility is that the CMB may have been affected by other sources of radiation, such as cosmic rays or radio galaxies. Another explanation could be that our current methods and technology may not be sensitive enough to detect small distortions in the CMB.

5. How does the failure of the intergalactic shadow test impact our understanding of the Big Bang theory?

The failure of the intergalactic shadow test does not necessarily impact our understanding of the Big Bang theory. It is just one piece of evidence in a larger body of research that supports the theory. However, it does provide support for the idea that the universe is homogeneous and isotropic on a large scale, which is a key aspect of the Big Bang theory.

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