Comments about the News & Views article in Nature: Missing matter found in the cosmic web

Following is a discussion about this Article in Nature Vol 558 21 June 2018, by Taotao Feng

To read the article select: https://www.nature.com/articles/d41586-018-05432-2

In the last paragraph I explain my own opinion.

Introduction

The article starts with the following sentence:
We live in a dark Universe: just 5% of it consists of ordinary matter such as that found in atoms, whereas the rest is ‘dark’ matter and energy that cannot currently be detected directly.
The fact that the word dark is written between ‘’ is remarkable. This implies a certain uncertainty or doubt.
Accordingly to: https://en.wikipedia.org/wiki/Dark_matter the mainstream opinion holds:
In the standard Lambda-CDM model of cosmology, the total mass–energy of the universe contains 4.9% ordinary matter and energy, 26.8% dark matter and 68.3% of an unknown form of energy known as dark energy. Thus, dark matter constitutes 84.5% of total mass, while dark energy plus dark matter constitute 95.1% of total mass–energy content. Etc
The primary candidate for dark matter is some new kind of elementary particle that has not yet been discovered, in particular, WIMPs, or GIMPs.
In the next sentence we read:
However, observations of the nearby Universe suggest that up to 40% of this ordinary matter — which is made up primarily of particles known as baryons — is missing.
This is interesting. The common accepted opinion was that the missing matter is non-baryonic and now this has changed to baryonic This means the complete opposite.
Next we read:
Baryonic matter is thought to be distributed through the Universe like a cosmic web, and the missing baryons are predicted to be located in the filamentary structures that connect the web, and in intergalactic space
It seems quite logical that there is a lot of baryonic matter in intergalactic space.
By combining the X-ray data with measurements of the ultraviolet emissions from 1ES 1553+113, Nicastro et al. estimated the density of the baryons associated with the X-ray absorbing features, and found that they account for 9–40% of the cosmic baryon density — suggesting that these features are a substantial reservoir of the missing baryons.
A more quantitative evaluation seems necessary.

Reflection

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Created: 24 May 2018

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