The Strange Case Of The Frankenstein Galaxy: UGC 1382

Frankenstein is a classic Gothic horror story written by the English author, Mary Wollstonecraft Shelley, who was also the lover, and later the wife, of the romantic poet Percy Bysshe Shelley. The novel was published anonymously in London in 1818, when Mary was only 20 years old, and it tells the chilling tale of a young–and possibly mad–arrogant science student named Victor Frankenstein, who creates a hideous and somewhat tragic creature in an unorthodox, and very unwise way–by putting his monster together from the assorted spare body parts of dead human beings. In 1814, when Mary and some of her companions were in Switzerland, occult ideas became the topic of some very imaginative conversations–and Mary was especially influenced by her future husband, Percy Shelley. Mary, Percy, the English romantic poet Lord Byron, and the English romantic writer and physician John Polidori, who is sometimes credited for creating the vampire genre of fantasy fiction, decided to engage in a friendly competition against one another to see who could write the best horror story. After thinking about it for days, Mary had a dream about a scientist who created life–only to be horrified by what he had made. Mary’s dream ultimately evolved into her Frankenstein novel.

Sometimes Nature imitates art, and in July 2016 NASA astronomers announced their discovery of a “Frankenstein” galaxy far, far away that appears to have formed from the assorted parts of other galaxies–both young and old. The enormous galaxy UGC 1382, which is located 250 million light-years from Earth, was at first thought to be a quiet, and rather unremarkable structure–as galaxies go–but the new study published in The Astrophysical Journal reveals the hideous secret of the formation of the “monster” galaxy UGC 1382, originally mistaken to be small, old, and typical–but is instead a strange structure built from the spare parts of others.

Astronomers, using data derived from NASA telescopes and other observatories, determined that UGC 1382 is about 10 times larger than previously thought and, in a way that differs from most galaxies, has insides that are younger than its outsides–which can only happen if a galaxy is built with the spare parts of others, just like Frankenstein’s monster.

“This rare, Frankenstein galaxy formed and is able to survive because it lies in a quiet little suburban neighborhood of the Universe, where none of the hubbub of the more crowded parts can bother it. It is so delicate that a slight nudge from a neighbor would cause it to disintegrate,” study co-author Dr. Mark Seibert commented in a July 11, 2016 NASA Jet Propulsion Laboratory (JPL) Press Release. Dr. Seibert is of the Observatories of the Carnegie Institution for Science in Washington, D.C. The JPL is in Pasadena, California.

Dr. Seibert and Lea Hagen, a graduate student at Pennsylvania State University in University Park, discovered this bizarre galaxy as a result of scientific serendipity. Serendipity means that while you are searching for one thing, you find something else instead. The two astronomers had been looking for stars being born in common elliptical galaxies, when they found UGC 1382 instead. Elliptical galaxies do not spin, and they show a more three-dimensional football shape than the flat disks that are sported by spinning pin-wheel shaped spiral galaxies, such as our own Milky Way, that possess arms twirling around the central disk. Astronomers at first thought that UGC 1382 was an ellipical.

However, while the astronomers were studying images of galaxies in ultraviolet light through data that they had obtained from NASA’s Galaxy Evolution Explorer (GALEX), a monster of a galaxy began to slowly emerge from the shadows of the dark and eerie space between galaxies, revealing its mysterious, spooky, and gigantic presence.

“We saw spiral arms extending far outside this galaxy, which no one had noticed before, and which elliptical galaxies should not have. That put us on an expedition to find out what this galaxy is and how it formed,” Hagen, who led the study, explained in the July 11, 2016 JPL Press Release.

Of Ellipticals, Spirals, And Others

A multitude of star-fired galaxies inhabit the visible, or observable, Universe. The visible Universe is that relatively small domain of the entire unimaginably vast Cosmos that we are able to observe. The strange and very remote domains that exist beyond our observable Universe reside far beyond the reach of our visibility, because the light flowing out from objects dwelling in those faraway and mysterious regions has not had sufficient time to reach us since our Universe was born in the Big Bang almost 14 billion years ago.

The hierarchical bottom up theory of galactic formation proposes that large galaxies–such as our own–were rare structures in the ancient Universe, and that galaxies only eventually reached their large and majestic sizes as a result of collisions between much smaller, shapeless protogalaxies, that bumped into one another and then merged in the crowded primordial Cosmos, that was quite a bit smaller than it is today.

Disk galaxies, which include galaxies with magnificent starry spiral arms–like our own Milky Way–and those with less well-defined structures known as lenticular galaxies are defined by their possession of pancake-shaped areas composed of dust and gas that distinguish them from their elliptical galactic cousins.

According to the system of galaxy classification, spirals like our Milky Way, are made up of rotating, flat disks composed of glittering, fiery stars, dust, and gas, as well as a central concentration of sparkling stellar inhabitants termed a bulge. These galaxies are encircled by a much fainter halo of stars, a large population of which dwell in globular clusters. Spirals are named in honor of their remarkable and beautiful spiral arms that reach out from the central heart of the galaxy into the disk. In contrast, ellipticals display approximately ellipsoidal shapes and a smooth and almost featureless brightness profile. In a way that differs sharply from their flat spiral kin, that show both organization and structure, ellipticals are more three-dimensional, with very little structure. The stellar denizens inhabiting ellipticals travel in, more or less, random orbits around the centers of their galactic hosts. Lenticulars are intermediate between spirals and ellipticals. This is because they share kinematic attributes with both types of galaxies. In fact, lenticulars are frequently called “armless spiral galaxies.” This is because lenticulars possess a bulge, but display no spiral arms.

The Frankenstein Galaxy

The team of astronomers, led by Lea Hagen, are currently trying to determine why the weird components of UGC 1382 are so different from those of other known galaxies–with the outside older than the inside.

First, the researchers studied data of the galaxy obtained from telescopes other than GALEX: the Sloan Digital Sky Survey (SDSS), the Two-Micron All-Sky Survey (2MASS), NASA’s Wide-field Infrared Survey Explorer (WISE), the National Radio Astronomy Observatory’s Very Large Array, and Carnegie’s du Pont Telescope located at the Las Campanas Observatory in Chile. After GALEX had unveiled previously hidden structures to the astronomers, optical and infrared light observations derived from the other telescopes enabled the scientists to build a new model of this mysterious, bizarre, galactic “monster”.

UGC 1382, at about 718,000 light-years across, is over seven times wider than our Milky Way. It is also one of the three largest isolated disk galaxies ever discovered, according to the study. This behemoth of a bizarre galaxy is a rotating disk of low-density gas. Stars cannot be born very quickly in this galactic “monster” because its gas is too diffuse.

However, the biggest surprise in store for the astronomers was how the relative ages of UGC 1382’s components appear to be going in the opposite direction of most of its galactic kin. In the case of most galaxies, the innermost portion forms first and harbors the oldest population of stars. As the galaxy grows, its outer, newer regions come to possess the youngest stars. However, in the case of UGC 1382, this proved not to be the case. By combining observations obtained from numerous telescopes, the team of astronomers were able to trace the historical record of when the Frankenstein galaxy’s stars were born–and their discovery proved to be bizarre.

“The center of UGC 1382 is actually younger than the spiral disk surrounding it. It’s old on the outside and young on the inside. This is like finding a tree whose inner growth rings are younger than the outer rings,” Dr. Seibert commented in the July 11, 2016 JPL Press Release.

The unusual, and so-far unique structure, of UGC 1382 may have been caused when separate galaxies met and then merged together, instead of by a single, solitary galaxy that grew outward–which is the way of most galaxies. This means that two parts of the Frankenstein galaxy may have evolved separately and independently prior to this merger. Each one of the merging galaxies preserved its own independent history.

The construction of UGC 1382 is thought to have begun with a group of small galaxies that were dominated by gas and dark matter. Dark matter is a transparent and, therefore, invisible substance that accounts for about 27 percent of the energy and matter content of the Cosmos. Dark matter is thought to be composed of exotic non-atomic particles that do not interact with light or any other form of electromagetic radiation–which is why it is invisible. Our own “ordinary” atomic matter–that composes the world that we are familiar with–accounts for a mere 5 percent of the Universe.

Eventually, a lenticular galaxy formed near the group of small galaxies, and at least 3 billion years ago, this rotating disk devoid of spiral arms exerted its powerful gravitational attraction on the smaller galaxies, which may have then fallen into orbit around the lenticular. Eventually all of the galaxies taking part in this Cosmic drama settled into the wide disk that astronomers observe today.

More galaxies like UGC 1382 may well exist in the Universe, but additional research is needed in order for astronomers to go on the hunt for them.

“By understanding this galaxy, we can get clues to how galaxies form on a larger scale, and uncover more galactic neighborhood surprises,” Hagen noted in the July 11, 2016 JPL Press Release.

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