TOP 5 OF THE MOST VOID AND SUPER VOIDS PLACES IN THE UNIVERSE.
In the observable Universe, there are very mysterious objects such as emission galaxies,
neutron stars, or supermassive black holes. But, just as these famous objects can be full of
mysteries, questions can also arise when we find places where there is absolutely nothing; after
all, Why should there be a Void in the Universe? These are the five most terrifyingly Void
in the Universe.
By definition, an astronomical void is a space with few or no galaxies in it. These Voids and
galactic superclusters are the most significant things in the observable Universe as they can
measure several hundred million light-years. In addition, they are considered very rare
since scientists fail to reach a consensus on how they are formed or how much they can grow.
1. TAURUS VOID The first of these is the Super Void of Taurus,
an immense region of almost Void space, located between the Supercluster of Perseus-Pisces
and the Supercluster of Virgo. The Taurus Void is unique because of its relative proximity to Earth.
Despite being the closest super Void to Earth, it is tough to study because it is located
behind the Evasion Zone called (ZOA), which is the area of the sky obscured by the Milky Way.
Everything behind the evasion zone is practically invisible to our telescopes since the greatest
concentration of stars is located that block with their light all the objects at a greater distance.
It's like wanting to see a firefly behind the lights of the floodlights of a football stadium.
But how do we know that the area is Void if we can't see it?
Scientists in charge of research in this region of the sky have always had problems
determining the diameter and density of the Taurus Void. Still, it has been possible to
observe this area previously with spectroscopes. Spectroscopes are special telescopes equipped with
lenses capable of seeing frequencies of radiation that our eyes do not perceive, such as ultraviolet
light infrared light, among many others. The infrared light region is where there is minor
foreground extinction of the Milky Way; observing in this region, we can see through all the stars
that are concentrated in the center of our galaxy. Thanks to this, it was established that the Void
of Taurus is a Void. In addition, other studies have mapped the Void,
and it has been shown that there is a rate of exit of galaxies from the Void to the outside of it.
That is, galaxies move away from the Taurus Void, moving in the opposite direction to the center;
our galaxy, the Milky Way, also continuously moves away from this Void, but... Why?
The Voids are thought to have been caused by oscillations of matter during the Big Bang:
mass collapses followed by implosions. These oscillations resulted in slight
differences in mass distribution in the early Universe that grew over time.
The dense areas collapsed more rapidly under gravity and created the foam-like
structure of the filaments and voids of galaxies we observe today. In contrast,
the areas that imploded did not form the filament of the galaxies, leaving them completely Void.
In this way, the galaxies are grouped into galactic clusters, while the Voids remain more
and more Void since the galaxies inside them are attracted by the concentrations of matter
outside the Void. 2. LOCAL VOID
This is a vast vacía region of space adjacent to the Local Galactic Group;
it was discovered by American astronomers Brent Tully and Rick Fisher in 1987; thanks to their
investigations, it is now known that the Local Void is composed of three sectors separated
by bridges of very faint galactic filaments. That is to say that in the middle of the Void,
there are regions with very few tiny galaxies; this means that the Voids are not completely
Voids but are much less dense areas than the rest of the Universe, which is still
something very rare for cosmologists who study the evolution of the cosmos.
Thanks to this Void, Astronomers have noticed that the Milky Way is located in a large flat matrix of
galaxies called the Local Leaf, which borders the Local Void. The Local Void extends approximately
200 million light-years starting at the edge of the Local Group. It is believed that the distance
from the Earth to the center of the Local Void must be at least 75 million light-years,
but we are moving away from it quickly. The size of the Local Void was calculated due
to the dwarf galaxy ESO 461-36 located inside; this galaxy travels at 135 miles per second
through the Local Void to an area where there are another group of galaxies outside the Void.
By comparison, the Milky Way and its neighboring galaxies in the local cluster are moving away
from the Void at 175 miles per second. This is because the Void, as the name implies,
lacks matter and therefore has no influence of gravitational attraction on other galaxies
that leave the Voids emptier and emptier. The larger and void a Void is, the weaker its
gravity and the faster galaxies within it flee to areas with higher concentrations of matter.
However, it has been observed that the dwarf galaxy ESO 461-36 that lies within the Local Void
is moving strangely fast, and some cosmologists are giving rise to the theory that perhaps
these regions have a significant dominance of dark energy, which would accelerate the galaxies
causing them to be ejected faster from the Voids. 3. BOOTES SUPER VOID
This is one of the most studied Voids in the Universe because it is one of the largest;
the Bootes Void was discovered in 1981 and is located near the constellation of the same name.
At 250 to 330 million light-years across, the Bootes Void is one of
the enormous Voids we have ever discovered. So far, 60 galaxies have been discovered in
the Bootes Void, so it's not entirely Void. As we mentioned before, the Voids are not 100%
Void since they have galaxies inside them; however, they are highly Void
regions if we consider that in a radius of 330 million light-years,
there should be between 2000 and 3000 galaxies, but in the Bootes Void there are only 60.
That's less than 1% of what's generally in such a large space.
What happened to the other galaxies? Where did they go?
What caused them to get out of there? Is anything inside the Voids that
causes galaxies to fall out of place? Are those galaxies there, but we can't see them?
All those questions still don't have a clear answer.
Studies indicate that the 60 galaxies found within the Bootes Void are concentrated in
a tube-like line that runs through the entire Void, so many researchers think
that the merger of several smaller Voids most likely formed the great Bootes Void.
This would mean that the networks of galaxies that we can observe in the Universe are
directly related to the Voids that also can merge to create larger, more massive Voids.
4. ERIDANIUS SUPER VOID The great Eridanius Super
Void is an area that can exist between us and the Cosmic Microwave Background (CMB).
Although there is evidence of its footprint in the form of cold, its existence is still debated. When
observing with radio telescopes, traces of galactic clusters have been detected inside.
What is not known is how dense these clusters are and how many there are.
In Super Voids like this, the temperatures are much lower than usual;
this can be seen in the image of the Cosmic Microwave Background where the areas with the
highest density of galaxies are marked with the color red, while the areas with the lowest density
of galaxies are represented with the color blue. In turn, the areas with the highest density of
galaxies are also the hottest, and the areas with the lowest density of galaxies are the coldest;
this means that if there are a large number of galaxies or cosmic dust inside the Voids, they
may be so cold that our telescopes are not able to detect it since they hardly emit radiation.
Scarce objects have been detected within the super Voids called "Void Galaxies," consisting
of galaxies whose star population is extremely low, but their behavior is that of a galaxy.
These Void galaxies are naturally cold and difficult to detect;
if they exist in a large proportion within this super Void,
then it would have much more matter than we can see with modern technology.
The Voids within the local group are relatively close to less than 800 million light-years,
being so close to the Milky Way it is possible to determine its density. Still,
in the case of the super Void of Eridanus, it is 10 billion light-years away, so it is impossible
to estimate its density with modern technology. We will have to wait for images from much more
powerful telescopes such as the James Web or the Very Large Telescope to solve these mysteries.
Suppose this Void is indeed as large as estimated to be one of the most significant structures
in the observable Universe that would measure approximately 150 to 300 Mega Parsecs.
In that case, this is equivalent to a diameter of between 500 million - 1 billion light-years.
5. CANES VENATICI SUPER VOID This is the most significant super
Void confirmed to date with an estimated diameter of 300 to 400 Mega Parsecs,
i.e., 1000 to 1300 million light-years. The Super Vació de Canes Venatici was
discovered in 1988 and is even more significant than the hypothetical "Eridanus Supervoid."
Although it is a large Void, there are 17 galaxy clusters concentrated in a spherical region
of 50 Mega Parsecs in diameter. Studies of the motion of clusters show that they
do not interact with each other, which means that the density of clusters is very low, resulting in
weak gravitational interaction. As with other detected SuperVoids,
this one also presents a pattern in which the galaxies inside accumulate
in a network of galactic filaments moving away from the center of the Void at high speed.
EXTRA: THE KBC VOID
The KBC Void is theoretically the largest known Supervoid; however,
like the Eridanus Supervoid, it is still debated whether this zone is a Void or not.
It has been shown that galaxies within a Void experience a gravitational pull from
outside the Void, which produces a higher local value for the Hubble constant. Remember that
the Hubble constant is a cosmological measure that helps us determine how fast the Universe
expands by measuring the redshift of galaxies. Some researchers have proposed the KBC structure
as the cause of the discrepancy between the Hubble constant measurements using galactic
supernovae and Cepheid variables and the cosmic microwave background to measure the
expansion of the Universe, which would mean that the Milky Way and the entire
galactic local group of which we are part are located right on the edge of superVoid KBC.
However, other work has shown no evidence of this in observations,
finding that the scale of the supposed galactic sub-density within the SUPERvoid KBC
is incompatible with observations extending beyond its radius; this would mean that this region is
not Void but rather moves at a different speed from the rest of the galaxies in the Universe.
For now, this is still under debate; if the following technologies
show us information about this region of the sky and it turns out that KBC's SuperVoid is real,
this would have a diameter of at least 2,000 million light-years, which would make it not
only the emptiest area of the known Universe but also the largest structure in the entire Universe.
Can you imagine that? The biggest thing in the Universe would be a bunch of... nothing.
SOURCES OF INFORMATION: 1.
http://mkweb.bcgsc.ca/universe-superclusters-and-voids/ 2.
https://asd.gsfc.nasa.gov/blueshift/index.php/2013/07/30/jasons-blog-next-stop-voids/ 3.
https://www.theguardian.com/science/2015/apr/20/astronomers-discover-largest-known-structure-in-the-universe-is-a-big-hole
4.
https://futurism.com/impossibly-large-holes-in-space-present-us-with-a-cosmic-quandary