(First a warning, this article is a translation of the spanish version, so it’s very likely to contain mistakes. That’s the author’s fault for not paying very much attention to the English grammar when he was young. Now he is learning so we hope you understand the situation and we are sorry for that. We will be happy to correct anything if you warn us.)
One of the tasks you have to do if you want to publish a game at Google Play, App Store or any other app store, is to create a few promotional images. That’s not the most exciting task of the world, but since you do it, try to do it getting something positive out of it, right? There is usually an eternal debate about the issue of how to explain to the player the game mechanics (tutorial or not tutorial? that’s the question), so we decided to solve the problem by using the pictures as instructions manual and this way we don’t annoy so much to the player.
The creation of the images was a mix of work in which the design comes from the Isaias’s mind, while the adaptation to the different formats, and some alteration, was mine.
In the planning phase of the task we thought that we have to use copyright free pictures and, if possible, from real space. From that occurrence comes this post, because while I was preparing the images and searching on my own a background image, I couldn’t help but entertaining myself seeking information about everything I was seeing. Everything I found made me wonder another thing, entering in an endless loop from which it was so difficult to get out. I cannot help it, I defend that this is one of the coolest things of doing what you love: to have the chance of learn new things along the way.
My intention is to explain everything that caught my attention, starting from the image that Isaias chose as background of our promotional images. The divagation process will be very similar to the one that my mind followed so I will be jumping from one thing to another as they appear.
I don’t know what will be your oppinion, but most of the time I was supposed to dedicate to promotional images task it was gone by admiring the beauty of the photographs or enjoying the explicative animations.
Anyway, the great artistic eye of Isaias finally choose the perfect picture (taken by the Hubble space telescope) and shows the galaxy NGC 1316 or Fornax A.
Now that we have made our mind with the picture, we have the opportunity to learn about it, because it has an interesting story behind.
This is a lenticular galaxy located in the “Fornax” constellation (fornax is furnace in latin). It has the A letter in its name because it is the brightest radio source of the constellation. It is situated at about 60 million light years and apparently has had a rather turbulent past. Much it is so that articles can be found where they refer to it as a “galactic serial killer”. Why? Because evidence suggests that it has been formed over billions of years based on absorbing other spiral galaxies. Hence it is not precisely small and has some visible “battle scars” such as dust clouds that crosses the galaxy from end to end.
As a personal comment, that kind of events seems to me as of such a gigantic scale, so overwhelming, that I think that our small minds can’t get a clear idea of what should it be to have two galaxies colliding against each other. The worst is that as for what I’ve read preparing this post it should not be so uncommon in the universe.
Another rather curious thing is that this galaxy has a little travel companion, the NGC1317. According to the information that I’ve read it is not clear to me if its gigantic partner is devouring it or it was devoured and now those are the remains that are left after their collision (I believe it is the latter). What it is clear is that they are quite close to each other and they leave us a beautiful picture.
At this point, I at least, I was wondering many things: Are there more than one kind of galaxy? And what is a lenticular galaxy? Are there galaxies that devour one to each other? What consequences has that?
Answering gradually, it turns out that galaxies can be classified into four types (based only in its appearance, yet there are other ways to classify them): elliptical, lenticular, spiral and irregular. The first three types can be grouped as regular galaxies.
The lenticular galaxies are just an intermediate type between the elliptical and the spiral. This kind of galaxies are characterized by having consumed or lost almost all of its interstellar medium (the dust/matter that lies between the stars and planets) and also, as in the elliptical ones, they lack the arms of the spiral galaxies therefore its stars are distributed quite uniformly along all the galactic volume.
Another remarkable aspect about our beloved lenticular galaxy “Fornax A” is that due to the peculiarities of its formation (galaxies collision), at its center it has been being fed a supermassive black hole with an estimated mass of about 130 – 150 million solar masses. Yes, the killer instinct of “Fornax A” has created an epic monster in his insides as figures such as these just can get us dizzy.
All questions answered, right? Now the problem is that after learning about these type of galaxies, what catches my attention are black holes. I don’t know what would be your opinion but after seeing “Interstellar” it looks to me that the black holes seem to have become an object of desire.
Relax, don’t feel envy of “Fornax A”. Our “Milky Way”, according to the available data, appears to have also one!. Its name is Sagittarius A* which in scientific jargon has been cataloged as: “a compact and extremely bright radio source” and is considered the most plausible candidate to be the supermassive black hole of our galactic center. Earlier I told you that the A was given to the brightest radio sources, this has also an * for, and I quote wikipedia: “emphasize its excited nature, that way establishing an analogy with the excited states of the atom, that are noted with an asterisk (Fe*, He*, etc…)”.
I suppose that you would like to know the size of our supermassive black hole, to compare with “Fornax A”, ours reaches 4 million of solar masses. We are quite below, but maybe it is better like that.
Here you can see Sagittarius A* thanks to the Chandra X-Ray Observatory.
At this point begins to become clear why one of the most widespread theories about galactic formation is that you can find in the center of almost any regular galaxy (eliptical, lenticular and spiral) a supermassive black hole. Being one of the elements responsible of keeping all the stars together thanks to its enormous gravitational pull.
Returning to lenticular galaxies (which keep me fascinated thanks to their peculiar forms) and their supermassive black holes, I found an image that I loved, from the NGC 5128 or “Centaurus A” galaxy (now you know why the A).
And what is so special about this picture?
The two jets of matter you can see in the picture emerging from the center of the galactic disk. They allow me to talk about a very peculiar effect that black holes can cause. Let me explain myself, those jets of matter in astronomy are (surprisingly) called “relativistic jet”. The jets are generally associated to accretion discs, a phenomenon that occurs in the formation of both stars and black holes. As a curiosity, these jets can reach relativistic velocities and may seem, from Earth, that they travel faster than light, but that doesn’t mean they really move faster than light, just that they seem to do it due to an optical effect caused by relativity.
In the picture below, taken from this article, you can see the different elements involved in the creation of the “jets”.
“Centaurus A” is believed to have in its center a supermassive black hole with a mass equivalent to 55 million solar masses (it can’t beat “Fornax A”, but our ” Sagittarius A*” looses again in this comparison of galactic muscle). This black hole feeds from the matter than spins around, creating what it is known as accretion disk. This disk spins at great velocities around the black hole getting hot and shining, but not all the material is swallowed by it. Some particles are ejected outside the plane of the disk, forming the two jets of matter that travel approximately at half the speed of light and extend along one million light years. Quite impressive.
Well dear readers, after reviewing “Centaurus A” I think that it is enough and that we have learned a few things. I hope that you have enjoyed everything I have told you and, at the same time, to have aroused your curiosity about space.
And that’s why I want to share with you one last thing I’ve found, which is something worth of talking, the irregular galaxies. Here it is the particularly beautiful picture of a ring shaped galaxy with the suggestive name of “Hoag’s Object”.
This time I leave to you the research and we would love if you share in the comments any curious thing you find.
Greetings from the Damn Code team.
Sources (not linked in the text):