This episode's coordinates point to the spiral galaxy NGC 2639, which is located at a distance of roughly 168 million light years (51.5 Mpc) [1] in the constellation Ursa Major. This object does not look like a particularly spectacular spiral galaxy, and it's also not particularly close, but it does have an active galactic nucleus (AGN) consisting of a supermassive black hole millions or millions of times the mass of the Sun, a disk of infalling gas around that black hole, and jets of gas emerging above the poles of the AGN that are from ionized gas that get deflected away from the black hole by its magnetic fields. What's important to keep in mind is that a large fraction of the gas orbiting a black hole might not even fall into it but end up in the jets, and this will be important for discussing NGC 2639. The AGN, and more specifically the jets, are what makes this galaxy very unusual, and most of what I'll be talking about in this episode is from papers published in 2019 and 2023 by groups led by Biny Sebastian and Vaishnav V. Rao.
The ionized gas in the jets from AGN typically produce strong radio emission originating from electrons oscillating around magnetic fields within the jets, making them extremely easy to find and to study with radio telescopes. Detailed radio observations of NGC 2639 with multiple radio telescopes, including the Very Large Array, the Very Long Baseline Array, and the Giant Metrewave Radio Telescope, showed that the AGN in this specific galaxy has radio emission associated with four different set of jets [2, 3]. These jets point in multiple different directions and have multiple different sizes. The largest jets extend outwards roughly perpendicular to the galaxy to a distance of about 15000 light years (4.5 kpc) [3], while the smallest jets consists of just a single blob of gas that has travelled about 10 light years (3 pc) from the center of the AGN in a direction that is almost directly into the disk of the galaxy [2, 3]. These jets would only appear when something is falling into the black hole at the center of the AGN, so the four different sets of jets imply that gas fell into the AGN at four different times from four different directions.
What most people think happened is that a series of small galaxies collided with NGC 2639 during time periods ranging from 2.8 to 34 million years ago [3]. Every time this happened, a lot of the gas from the smaller merging galaxy would end up falling into the center of NGC 2639 and therefore would probably end in that disk of gas surrounding the black hole in that AGN, and while some of the gas would fall into the black hole itself, some of the gas would end up being deflected by the AGN's magnetic fields into the jets. The smaller galaxies would have also fallen inwards in different directions. If something slid into the center of NGC 2639 through the plane of the spiral galaxy, then the disk that would have formed around the black hole at the center would be aligned with the disk in NGC 2639, and the jets would point out of the plane of the galaxy. However, when something hit NGC 2639 in a perpendicular direction, then the gas falling into the AGN would be tilted relative to NGC 2639's disk, and the emerging jets would actually plow into the gas and stars in NGC 2639's disk. Additionally, the large amount of gas that has been expelled from the AGN through its jets, especially the gas blown into the disk of the galaxy, would have disrupted the formation of stars from interstellar gas in NGC 2639 by either blowing away the gas or making the gas too hot to gravitationally collapse [3]. The term that astronomers use for this is feedback.
So, the weird multiple sets of jets pointing in multiple different directions is very unusual, and finding such jets in NGC 2639 is what makes this galaxy really stand out. However, I know from attending conferences devoted entirely to AGN feedback disrupting star formation that, while such feedback was quite common when the universe was a few billion years younger, it's very hard to find in nearby galaxies, and I'm a little surprised that the AGN feedback in NGC 2639 hasn't received even more attention. Maybe that will change in the future.