Bootes void

[Bmpbmp1975]

Here is an interesting thought, what if the bootes void is really the product of vacuum decay or collapse?
and these voids we are seeing are product of the Higgs field dropping?

had this ever been thought Or discussed?

Edited February 17, 2020 by Bmpbmp1975

[Ghideon]

15 minutes ago, Bmpbmp1975 said:

Here is an interesting thought, what if the bootes void is really the product of vacuum decay or collapse?
and these voids we are seeing are product of the Higgs field dropping?

had this ever been thought Or discussed?

Do you mean Boötes Void*?

I see no reason why this void is not consistent with current models of the universe. The void is not explained by vacuum collapse. 

Vacuum collapse will, AFAIK, spread wit the speed of light, or close to the speed of light, i vacuum. So the fact that we are here discussing this matter is a hint that vacuum decay did create the Boötes Void we observe. 

 

https://en.wikipedia.org/wiki/Boötes_void  (Just checking, it may be spelled differently in different languages)

[Strange]

50 minutes ago, Bmpbmp1975 said:

Here is an interesting thought, what if the bootes void is really the product of vacuum decay or collapse?

As you know from you extensive reading, if a vacuum collapse were to occur it would spread at the speed of light.

So, no it isn't possible.

51 minutes ago, Bmpbmp1975 said:

and these voids we are seeing are product of the Higgs field dropping?

They are formed by gravity. Simulations reproduce the formation of these large structures.

If you follow "voids" link from the Wikipedia page that Ghideon mentions, it explains that:

Quote

Starting from initially small anisotropies from quantum fluctuations in the early universe, the anisotropies grew larger in scale over time. Regions of higher density collapsed more rapidly under gravity, eventually resulting in the large-scale, foam-like structure or "cosmic web" of voids and galaxy filaments seen today. Voids located in high-density environments are smaller than voids situated in low-density spaces of the universe

https://en.wikipedia.org/wiki/Void_(astronomy)

[Ghideon]

3 hours ago, Strange said:

They are formed by gravity. Simulations reproduce the formation of these large structures.

Good point regarding simulation, caught my interest:
@Bmpbmp1975: There are theories that voids can merge to form larger voids. Here is one article with short animations and references to papers:  https://www.nature.com/news/vast-cosmic-voids-merge-like-soap-bubbles-1.18583

Quote

The smaller voids that are approaching each other do so because they are embedded in parts of the web that have a higher than average density, he notes. Gravity would cause such regions to eventually coalesce and shrink. Larger voids tend to lie within patches of the web that have lower density, and are being pulled apart by the gravity of adjacent patches.

Another short article that specifically covers some ideas of the formation of Boötes: https://web.archive.org/web/20071119011039/http://findarticles.com/p/articles/mi_m1511/is_n8_v16/ai_17253874

Quote

Computer simulations have shown how smaller voids, which are much more common, can arise. As galaxies are pulled together by their gravitational attraction to one another, they empty out neighboring regions. The process is selfreinforcing

 

[Bmpbmp1975]

On 2/17/2020 at 4:10 PM, Ghideon said:

Good point regarding simulation, caught my interest:
@Bmpbmp1975: There are theories that voids can merge to form larger voids. Here is one article with short animations and references to papers:  https://www.nature.com/news/vast-cosmic-voids-merge-like-soap-bubbles-1.18583

Another short article that specifically covers some ideas of the formation of Boötes: https://web.archive.org/web/20071119011039/http://findarticles.com/p/articles/mi_m1511/is_n8_v16/ai_17253874

 

So are the 60 galaxies alive or dead galaxies?

[Ghideon]

36 minutes ago, Bmpbmp1975 said:

So are the 60 galaxies alive or dead galaxies?

The galaxies are of different kinds. Some are very alive*: (bold by me)

Quote

We investigate the physical properties of a sample of 26 galaxies in the Bootes void and classify these galaxies based on the emission lines in their spectra. Fourteen galaxies are classified as H II galaxies with properties similar to field H II galaxies. Two of these galaxies, 1432+5302 and 1507+4554, are extreme starburst galaxies. Approximately half of the galaxies with measurable Hα+[N II] emission have elevated rates of star formation. 

source: https://iopscience.iop.org/article/10.1086/324739

 

*) Alive=A galaxy creating new stars. Dead=a galaxy where star formation has stopped

Edited February 22, 2020 by Ghideon
Clarifying dead vs alive.

[taeto]

29 minutes ago, Bmpbmp1975 said:

So are the 60 galaxies alive or dead galaxies?

Unfortunately, scientists have so far not detected any life, intelligent or otherwise, present in any single one of these galaxies.

[Bmpbmp1975]

19 minutes ago, taeto said:

Unfortunately, scientists have so far not detected any life, intelligent or otherwise, present in any single one of these galaxies.

I meant are they still forming stars 

not that it really matters anymore 

[taeto]

3 minutes ago, Bmpbmp1975 said:

I meant are they still forming stars 

not that it really matters anymore 

Oh, okay, yes, they are mostly star forming, as Ghideon said already. But good that it doesn't matter, since then I do not have to feel bad if my answer is wrong.

[Ghideon]

11 minutes ago, Bmpbmp1975 said:

not that it really matters anymore 

Ok. May I ask why you posted the question then? And made members spend time posting answers?

 

[Bmpbmp1975]

1 hour ago, Ghideon said:

Ok. May I ask why you posted the question then? And made members spend time posting answers?

 

Sorry 

thank you all 

Edited February 22, 2020 by Bmpbmp1975

[Ghideon]

Adding some information: just as in denser regions, voids also contains galaxies that does not form stars anymore (dead galaxies):

Quote

Although galaxies in voids are observed to be predominately gas rich, star forming and blue, a subpopulation of bright-red void galaxies can also be found, whose star formation was shutdown long ago. Are the same processes that quench star formation in denser regions of the Universe also at work in voids?

https://academic.oup.com/mnras/article/386/4/2285/1467362

The conclusions are that the amount of dead vs star forming galaxies fits mainstream models and simulations.

Quote

Early-type ‘red and dead’ red-sequence galaxies appear naturally in the voids. They arises because of a shift in the halo mass function in low-density environments combined with an environment independent star formation shut-down mechanism efficient above a critical halo mass (here, radio-mode AGN). Together, these approximately produce the correct observed abundance.

More details available in the linked article. The article is rather old but may be an interesting start for further reading about void galaxies vs galaxies in denser regions and galaxy formation and evolution.

 

[Bmpbmp1975]

1 hour ago, Ghideon said:

Adding some information: just as in denser regions, voids also contains galaxies that does not form stars anymore (dead galaxies):

https://academic.oup.com/mnras/article/386/4/2285/1467362

The conclusions are that the amount of dead vs star forming galaxies fits mainstream models and simulations.

More details available in the linked article. The article is rather old but may be an interesting start for further reading about void galaxies vs galaxies in denser regions and galaxy formation and evolution.

 

So basically voids seem to hold galaxies that also still create stars then?

[Strange]

15 minutes ago, Bmpbmp1975 said:

So basically voids seem to hold galaxies that also still create stars then?

Yes, most of them are still active

[Bmpbmp1975]

1 hour ago, Strange said:

Yes, most of them are still active

That’s pretty cool, so dead galaxies and live galaxies can be situated is the same area of space 

how is that possible?

Edited February 23, 2020 by Bmpbmp1975

[Mordred]

The volume of spacetime is huge, some galaxies has enough plasma to produce new star formations however a nearby galaxy may not. I would go over the mathematics of the virial theorem in regards to Jeans instability which leads to filament cluster formation and voids and the relations between the two but very few readers would understand them.

Suffice it to say as matter gets attracted to the higher densities in filaments the amount of matter in voids reduce and gravity within the voids weaken as a result. This allows the void to grow while the filament becomes more dense.

A side note this is also the same process that allows a matter only universe to expand. In essence expansion also involves this process as well as Lambda. The process has nothing to do with the vacuum.

 

Edited February 23, 2020 by Mordred

[Strange]

10 hours ago, Bmpbmp1975 said:

That’s pretty cool, so dead galaxies and live galaxies can be situated is the same area of space 

how is that possible?

Why not. The ability to create new stars depends on many factors but, I assume, mainly the amount of hydrogen available and how it is distributed. Not all galaxies in a particular area are identical. They will have formed at different times, be different sizes, have experienced different things. Some may have stopped creating new stars and then started again after some even such as a collision with another galaxy caused gas to compress enough to start another period of star formation.