Introduction

Part of the Universe that we seldom talk about is the really dark and mysterious part of the Intergalactic space. We will talk about what we know about it and what we don’t.

Where do you think most of the matter in the Universe hides in? Where do you think we can find most of these so-called baryonic or visible matter? Automatically, most of us would answer that it’s in black holes, supermassive or ultra-massive.

The thing is, that’s not even remotely close to the truth. As a matter of fact, we need to go far away before we discover where most of that mass is. So, first of all, only a tiny fraction of mass is represented by black holes because a lot of the mass in the Universe is still sort of in gas form, basically free-floating. It hasn’t really become a star or was a star and then exploded, and this mess was rereleased, so most of the mass is just dust and gas. Most of it would not even be visible. Still, also, at the same time, if we wanted to discover the most significant source of mass, we would have to go outside of our Galaxy who has to go into the middle of the empty space known as the Intergalactic medium. So, today we’re going to be talking about what is really happening here in between galaxies and why this is most likely one of the biggest mysteries we still have and hides a lot of answers to the fundamental questions on the Universe.

Everything, whatever we discover here in the intergalactic medium it is actually a lot more important than what we find out in the middle of our Galaxy.

DIGGING LITTLE DEEPER

But what’s more interesting here is if you were choosing out with the Galaxy still being right there in the middle. Very small now, you’ll notice that there is actually a lot more gas all over the place in the middle of nowhere. Suppose we also started looking at dark matter; in that case, we’ll realize that tunnel-like formations we refer to as the galactic filaments are some of the most significant structures out there in the Universe, and along these tunnels or these filaments are other galaxies.

So pretty much every major Galaxy out there in the Universe is connected with these filaments filled with gas, occasional stars, and a lot of dark matter. If we were to zoom out here a little bit more, you would start seeing these formations pretty much everywhere. Now, if I were to remove the gas and only leave the stars behind, this is really what it kind of looks like. This is just Dark matter, and the visible matter, which is kind of what you’re looking at here, is well accepted. For the most part, if you were to remove all of the galaxies from the picture, you would still be left with roughly around 80% of the entire mass of the Universe. We’re talking about baryonic mass only, not even dark matter or anything. So essentially, more stuff out there makes up stars, and off, of course, that is outside of galaxies than inside those galaxies. So, all of this intergalactic space, basically the space between galaxies like the Milky Way and the Andromeda, is filled with these filaments that you see, and inside of them, there’s quite a lot of stuff just kind of staying there. Most of the stuff is actively interacting with each other. Much of it is made up of what’s known as ionized hydrogen, mostly because these regions of space are very, very hot, and they create these very highly energized molecules.

The nuclear reactions have two results: (i) they determine the energy output per unit time of a given shell which is used in the energy balance equation and (ii) they determine the abundances of elements involved in the nuclear reactions. The former is used in the energy balance equation and the latter is used to find the evolution of mean molecular weight. The standard model is constructed through an iterative method. First, an initial guess of mixing length parameter and helium abundance are considered and their evolution is found at the current age of the sun. Then these are compared to the observed values, and the discrepancy is adjusted by adjusting the mixing length and abundance.

WE ARE JON SNOW

Even today, we still have more questions about this part of the Universe than we have no answers. There are still many questions about the mysterious dark matter, how these filaments were formed to begin with, and many other questions related to the eventual fate and evolution of the entire Universe as it kind of flies apart and become bigger and bigger. So, we believe that one day maybe the Universe does some sort of rip apart, which means that all of these films will disappear. For now, though, we don’t really know. But what we can do today is continuously study these galactic filaments, and of course, the mysterious voids simultaneously simulating them here on Earth using supercomputers.

Hopefully, this way, we’ll now be able to one day understand what’s going on, how all this will evolve in the next few billion years.

References -

·       A computer simulation depicting a large chunk of our Universe by G. L. Bryan, M. L. Norman, UIUC, NCSA, GC3years.

·       The Dispersion of Fast Radio Bursts from a Structured Intergalactic Medium at Redshifts z < 1.5 by J. Michael Shull and Charles W. Danforth.