14 DAY TRIAL // Astronomers with the European Southern Observatory (ESO) were recently able to figure out the secrets behind the structure of a large galaxy designated NCG 1316. The object is now believed to be a cosmic serial killer, having destroyed and consumed multiple other galaxies throughout its tumultuous life span. Flying through space alongside it is its smaller companion, spiral galaxy NGC 1316.
The duo was recently imaged using the MPG/ESO 2.2-meter (7.2-foot) telescope, which is installed at the La Silla Observatory, on the outskirts of the Atacama Desert, in Chile. This installation is home to 10 telescopes, including the New Technology Telescope (NTT), the Danish National Telescope (DNT), the Euler Telescope, and the TRAnsiting Planets and PlanetesImals Small Telescope (TRAPPIST).
Even though NGC 1316 and NGC 1317 are located relatively close to each other, they have very little in common in terms of their evolutionary history. While the latter has led a relatively-uneventful history, its larger companion has had a rough ride, bumping into and consuming everything it came across. ESO astronomers are currently analyzing its battle scars to learn more about its history.
One of the first things that captured experts' attention was the unusual set of dust lanes that permeate the galaxy. These lanes are all embedded within a massive envelope of stars, a type of arrangement that can only be observed in galaxies with a rich history of undergoing mergers. Another hint is represented by the unusually-small globular star clusters that permeate its structures.
Scientists say that these clusters appear to point towards a merger that occurred as recently as 3 billion years ago – meaning the complex process was only concluded recently – where NGC 1316 consumed a very dust-rich spiral galaxy in its immediate vicinity. Similar scars can also be observed on the Milky Way, which is known to have devoured numerous dwarf galaxies, but to a smaller extent.
The ESO group was also able to distinguish very faint tidal Tails trailing the galaxy as it flies through space. These structures are composed of numerous stars that have been removed from their original locations within NGC 1316 by the complex gravitational interactions that develop when two galaxies collide, or fly very close to each other.
The fact that they are still visible today suggests that the galaxy has not yet renounced its disruptive behavior. The galaxy, also known as Fornax A, lies around 60 million light-years away from Earth in the southern constellation of Fornax (The Furnace). The reason why it bears the letter A in its name is that it is the most potent source of radio wavelengths in the entire constellation.
ESO experts say that the new image is actually a collage of multiple photographs collected by the MPG/ESO telescope. Stitching these views together allowed astronomers to tease out some of the fainter structures in and around the galaxy.