In the blog post, "It's Triplets", we began to consider the process of merging galaxies and included false color pictures and diagrams of these events. As promised, this posting will consider the possible effects of these mergers, and since most galaxies are host to black holes we will look at the possible impact of merging black holes. One might wonder if the universe is eating itself alive. Lets find out: read on.
Let's start by viewing NASA's movie of merging galaxies (simulation). Click MERGE to join in. Now keep in mind in the real world or universe these mergers would take millions even billions of years to come about, but the interaction is well illustrated by this NASA simulation. You can almost hear the crackle of energy and feel the power of the merger. In my mind this is not a dying universe, this is a ongoing, creative universe.
Actually, the coming together of galaxies is expressed by astro-scientists in three descriptive ways. They use the term interacting galaxies in which two, or as we have seen, three or more galaxies gravitationally interact. This is where their gravitational forces affect their respective structures. In about two to three billion years, our Milky Way galaxy and the Andromeda galaxy will begin to interact. Somewhere after that time, these two galaxies will begin to merge or collilde with one another.
The term merging galaxies refers to the process, similar to that depicted in the NASA simulation above. This is where galaxies literally come together to create a new and larger galaxy. Finally, as these two galaxies or others merge, and when their central nuclei are very close to one another, they can produce what these scientists define as starburst galaxies. This is where dynamic bursts of new star formation take place. This phenomenon is expected to take place when our galaxy and Andromeda finally merge billions of years from now. This Hubble image of galaxy NGC1569 is an example of a starburst galaxy. Now this is a small galaxy and until Hubble looked it over it was not considered a star maker. You might also notice the similarities between this galaxy's structure and that of the Crab Nebula due to their common central "hot" cores, but from entirely different origins and with equally different futures. In our opinion, these new star birthing cycles do not spell a distintegrating universe but rather one that is expanding and growing - infinitely.
Take a moment and review the previous blog post "It's Triplets" and look at the images. You will see visual examples of both interacting and merging galaxies. It is also possible that in the second image a starburst galaxy is about to occur. What do you think? To learn more on this topic, visit this link here. Additionally if you would like to see a bigger view of this little galaxy with a musical tribute to its star making efforts click here. Lastly, if you wish, click here to view an image of this galaxy taken on 11/22/08 from Slooh.com. You too can wander the universe as a Slooh.com member. Come join us.
We pause here. The discussion on colliding or merging black holes will follow in Part Two of this topic. We invite your questions and comments, please respond.