Missing Matter Found:

[beecee]

https://phys.org/news/2017-10-teams-astronomers-evidence-baryonic.html

(Phys.org)—Two teams working independently have found evidence of the existence of Baryonic matter—particles that link galaxies together. One team was made of members from the Institute of Space Astrophysics, the other was based out of the University of Edinburgh. Both teams have uploaded a paper describing their work to the arXiv preprint server and both are claiming their findings solve the mystery of where so much of the normal matter—protons, neutrons and electrons—in the universe has been hiding.

Once scientists came up with the Big Bang Theory, a problem immediately arose—after calculating how much normal matter should exist in the universe at this point in time, they found approximately 50 percent of it is missing. Since then, scientists have worked on theories to explain where all that matter was hiding—the prevailing theory suggests that it exists as strands of Baryonic matter floating in the space between galaxies and cannot be seen with conventional instruments—this was the theory both teams in this new effort tested.



Read more at: https://phys.org/news/2017-10-teams-astronomers-evidence-baryonic.html#jCp

 

the paper:

https://arxiv.org/pdf/1709.05024.pdf

A Search for Warm/Hot Gas Filaments Between Pairs of SDSS Luminous Red Galaxies

 

ABSTRACT

We search the Planck data for a thermal Sunyaev-Zel’dovich (tSZ) signal due to gas filaments between pairs of Luminous Red Galaxies (LRG’s) taken from the Sloan Digital Sky Survey Data Release 12 (SDSS/DR12). We identify ∼260,000 LRG pairs in the DR12 catalog that lie within 6–10 h −1Mpc of each other in tangential direction and within 6 h −1Mpc in radial direction. We stack pairs by rotating and scaling the angular positions of each LRG so they lie on a common reference frame, then we subtract a circularly symmetric halo from each member of the pair to search for a residual signal between the pair members. We find a statistically significant (5.3σ) signal between LRG pairs in the stacked data with a magnitude ∆y = (1.31 ± 0.25) × 10−8 . The uncertainty is estimated from two Monte Carlo null tests which also establish the reliability of our analysis. Assuming a simple, isothermal, cylindrical filament model of electron over-density with a radial density profile proportional to rc/r (as determined from simulations), where r is the perpendicular distance from the cylinder axis and rc is the core radius of the density profile, we constrain the product of over-density and filament temperature to be δc × (Te/107 K) × (rc/0.5h −1 Mpc) = 2.7 ± 0.5. To our knowledge, this is the first detection of filamentary gas at over-densities typical of cosmological largescale structure. We compare our result to the BAHAMAS suite of cosmological hydrodynamic simulations (McCarthy et al. 2017) and find a slightly lower, but marginally consistent Comptonization excess, ∆y = (0.84 ± 0.24) × 10−8 .

:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

 

Does this mean if further research validates these findings, that we will have less need for the quantity of DM that currently constitutes around 27% of the universe? 

Edited October 10, 2017 by beecee

[Strange]

43 minutes ago, beecee said:

Does this mean if further research validates these findings, that we will have less need for the quantity of DM that currently constitutes around 27% of the universe? 

I am not sure, but I thought that this "missing" baryonic matter was already taken into account (I mean, assumed to be there). But if it turns out to be largely outside galaxies, that might mean we need more dark matter not less!

[Mordred]

Its always been known that baryonic matter was not adding up right. However even with the addition of the baryonic matter its still not nearly enough to cover the amount of dark matter. Baryonic matter being roughly 4 percent compared to 23 percent. A huge difference

[swansont]

13 hours ago, beecee said:

Does this mean if further research validates these findings, that we will have less need for the quantity of DM that currently constitutes around 27% of the universe? 

This was matter that was part of the known baryonic matter but hadn't been detected yet. So, no.

[Dubbelosix]

Yes that's right. This is extra baryonic matter which has never  been detected.  

15 hours ago, Mordred said:

Its always been known that baryonic matter was not adding up right. However even with the addition of the baryonic matter its still not nearly enough to cover the amount of dark matter. Baryonic matter being roughly 4 percent compared to 23 percent. A huge difference

 

 

I don't know about you, but I have been keeping an eye on these kinds of developments. With much larger and more accurate mapping of the universe, we will not I predict only find the universe a much larger place, but probably has more mass than has been accounted for. A good example of how difficult this is can be demonstrated with the following article, which until recently, the Milky was hiding hundreds of galaxies. 

 

http://sciencevibe.com/2016/02/10/milky-way-surprise-its-been-hiding-hundreds-of-unseen-galaxies/

[swansont]

1 hour ago, Dubbelosix said:

Yes that's right. This is extra baryonic matter which has never  been detected.  

No, it's not extra. It's what was expected but had not yet seen.

"after calculating how much normal matter should exist in the universe at this point in time, they found approximately 50 percent of it is missing."

They found some of the missing matter that they had expected to find.

 

[Janus]

3 hours ago, swansont said:

No, it's not extra. It's what was expected but had not yet seen.

"after calculating how much normal matter should exist in the universe at this point in time, they found approximately 50 percent of it is missing."

They found some of the missing matter that they had expected to find.

 

That makes sense, I as understood that the universe couldn't have very much more baryonic matter than presently predicted without it having had a large effect on the early universe, and thus an effect on what the universe should look like today.

[beecee]

1 hour ago, Janus said:

That makes sense, I as understood that the universe couldn't have very much more baryonic matter than presently predicted without it having had a large effect on the early universe, and thus an effect on what the universe should look like today.

Also obviously effect the Omega figure and the geometry of the universe, ie open, closed or flat and that being close to the value omega=1, indicating a flat universe.

[koti]

"Two separate teams found the missing matter – made of particles called baryons rather than dark matter – linking galaxies together through filaments of hot, diffuse gas."

“The missing baryon problem is solved,” says Hideki Tanimura at the Institute of Space Astrophysics in Orsay, France, leader of one of the groups. The other team was led by Anna de Graaff at the University of Edinburgh, UK."

"Both teams took advantage of a phenomenon called the Sunyaev-Zel’dovich effect that occurs when light left over from the big bang passes through hot gas. As the light travels, some of it scatters off the electrons in the gas, leaving a dim patch in the cosmic microwave background – our snapshot of the remnants from the birth of the cosmos."

https://www.newscientist.com/article/2149742-half-the-universes-missing-matter-has-just-been-finally-found/

[koti]

Sorry for the mess folks, Not noticing this thread, I posted the above as a separate topic in the Science News section and it was (correctly) merged into this thread.