This episode's coordinates point to the spiral galaxy NGC 3110. Because of bookkeeping errors in the New General Catalogue, this galaxy is also known as NGC 3122 and NGC 3518. It also has about 20 other names, but I'm going to skip over that. Anyhow, this is a spiral galaxy that is seen kind of face-on as seen from Earth. The galaxy has a relatively small bulge in its center, a bright bar of stars running through the center of that bulge, and two relatively extended spiral arms. The object is located at a distance of 177 million light years (54.3 Mpc) [1], which means that it's too far to be an interesting amateur astronomy object but not so far to be considered beyond the local extragalactic universe. In many respects, it looks kind of ordinary, at least in the visible part of the electromagnetic spectrum.
In the infrared part of the electromagnetic spectrum, this galaxy is abnormally bright, and it belongs to the class of galaxies called Luminous Infrared Galaxies (LIRGs) [2]. In astronomy, infrared light (except for wavelengths close to visible light) is primarily produced by dust. That dust will absorb ultraviolet and visible light from stars and re-radiate that energy as infrared light. Many galaxies, including our own, contain interstellar dust and therefore produce infrared light, but what is happening in luminous infrared galaxies is more extreme.
One reason luminous infrared galaxies could be extra bright in the infrared is because they contain many brighter stars that are heating up the instellar dust much more that what would be seen in an average galaxy with relatively average stars. When stars form out of interstellar gas, they usually have a range of sizes. The biggest stars are very hot and very blue, but they also have very short lifespans before they explode as supernovae, so if astronomers see these big hot stars blue somewhere, they know that the stars must have formed very recently. We see these big hot blue stars forming in our galaxy and many others, but many luminous infrared galaxies contain an abnormally large amount of these blue stars because they are forming stars at an abnormally high rate.
However, galaxies usually don't just start producing abnormally large amounts of stars on their own. Something usually has to induce the formation of extra stars in these galaxies.
Star formation rates can increase dramatically when two galaxies merge together. When this type of event happens, the orbits of the old stars from the two galaxies get scrambled, while the interstellar gas clouds from the two galaxies will collide with each other, and this collision causes the gas to fall into the center of the object produced by the merging galaxies, which I will call a merger. The huge amounts of gas falling into the center of the merger will cause all of the interstellar gas clouds to collapse all at once to produce abnormally large numbers of new stars (including abnormally large numbers of big hot blue stars) that can provide extra heating to the interstellar dust that is present. This will result in the merger producing abnormally high amount of infrared emission, thus making the merger into a luminous infrared galaxy.
However, NGC 3110 is rather unusual among luminous infrared galaxies is that it is just beginning to gravitationally interact with a second galaxy, which is a smaller disk-like galaxy named MGC -01-26-013 [3, 4]. These two galaxies are separated by about 90 thousand light years (28 kpc). They are close, but they are still distinct objects, and the gas clouds in these two galaxies have not yet really collided with each other. It will take many more millions of years before they reach the stage in the merger process where the two galaxies have crashed together to form a weird mutant extragalactic object with chaotic stellar orbits and with all of its interstellar gas in its center.
So what is apparently happening is that the gravitational forces exerted by the smaller disk galaxy appear to have warped the disk of NGC 3110 [3, 4]. This is causing the interstellar gas clouds within NGC 3110 to collide with each other, and thiese collisions are causing the clouds to collapse and form lots of new stars. Some of these gas clouds are falling into the center of NGC 3110 and producing extra new stars and extra infrared emission there, but some of the other gas clouds in NGC 3110 seem to have been compressed into the spiral arm closer to the smaller disk galaxy, and the stars forming in that spiral arm are making it extra bright at infrared wavelengths [3, 4].
As far as luminous infrared galaxies go, NGC 3110 is a rather rare example of such a galaxy in the early merger process. To be clear, it's not the only such luminous infrared galaxy in this stage, but it is one of very few known examplesof this phenomenon in the local universe. As such, it has attracted attention from a few astronomers who want to understand the full story of how stars form during the entire merger process. Additionally, a significant fraction of the galaxies seen in the more distant universe at infrared wavelengths are luminous infrared galaxies, and even if a small fraction of those galaxies are early-stage mergers, it is still going to be important to identify how they form stars and produce such large amounts of infrared light. Hence, the relatively nearby NGC 3110 is going to be important for understanding many other luminous infrared galaxies across the universe.